DrOsOs

So having read this and other forums, finally took the plunge and decided to get my 2012 BRZ mapped.
Contacted Mike on the 18th Feb and he was very helpful, responding quickly to my initial enquiry and patiently responded to my numerous questions.
After a bit of back and forward I decided to go for the NA Tuning Package (UEL), MTEC Uprated Spring and Whiteline Positive shift upgrade kits and since TD would have the car for the best part of the day, decided to have the Billet Cam Plate kit fitted as a preventative measure at the same time.
Everything was arranged for the 7th of March and I was up and out on the road early (5:20am)  to make the trip south from Glasgow.
Arrived at 8:30am and Mike was 15 minutes behind me to open up.  Having handed over the keys, Mike was kind enough to give me a lift to the nearby UBC business centre (3 miles away) where I had booked an office for the day, I currently work mostly remotely from home so was able to effectively work there for the day, meaning I didn’t have to use a days holiday - result!
Picked the car up at 4pm and couldn’t be happier with the upgrades - drives like a different car with the dreaded torque did almost entirely gone with the increased lower rev torque noticeable across all the gears.  Gear changes are now much snappier and the exhaust note subtly enhanced.
Had a bit of a blether with Mike before heading off home, and ooh'd and ahh'd about possibly getting a turbo at some point in the future as well as a couple of options for dealing with the cars suspension, which I have been unhappy about almost from the day I bought it in the summer of 2015. Previous owner had lowered the car on Eibach sportline springs and I subsequently upgraded to 18" rims with the rear end especially, being very unforgiving with the car bouncing badly on rough roads.
Long story short, I was heading back down the M6 two weeks later, this time to get the BC Racing coilovers and the TD Super Resonated CAT back exhaust (my stock exhaust was corroded badly and very slightly beginning to blow so seemed like a good enough excuse).
I have not stopped smiling since ... ride quality and handling are 100% improved and the exhaust note is just loud enough to be noticeable, without being in your face but at the same time very civilised when cruising on the motorway.  
Can’t speak highly enough about Mike, Nick and the rest of the guys at TD. I was well looked after, their prices are competitive and the work has been carried out to a high standard. I have spent a fair chunk of change in anyone’s book in a short space of time, but every upgrade has had a noticeable and very positive effect, all in all it's like having a new car.
My only dilemma now is which kidney am I selling to fund the turbo upgrade? ...

Mike, despite me having no cats, I've had no issues with track day noise limits. Always seems to be well within.

Ok, so now I've got my insurance sorted I can now review this little lot...
After a bit of reading on here and elsewhere it seems the best gains to be had on an n/a car come from a manifold replacement. Much as I love the car, two key things that had slightly underwhelmed on the standard car from new we're the lack of mid range grunt, and the slightly characterless engine note.
So given that I'm in the North West I decided to get Mike at Tuning Developments to have a go at the car. I've basically had the upgrades he's now offering as a package, so k&n filter, custom decatted manifold and overpipe (sourced from a rather excellent local exhaust specialist) and an Ecutek tune to suit.
TD offer EL and UEL manifolds. I went UEL because this is a boxer and I wanted it to sound like one . I have memories of Colin McRae in flying Imprezas... Etc etc
So what's it like? Really good. The torque dip is gone. What this means in practice is that the car bogs down much less - on most B roads you could basically stay in 3rd if you're feeling lazy. There's enough extra top end to make it feel quicker than it was before - the engine now feels a better match for the chassis. This is how I wish it had come from the factory, and how it probably would have done ten years earlier...
Any downside? No not that I can think of. Fuel consumption seems identical as far as I can tell. And while the engine note is more characterful and definitely louder under throttle, with the standard exhaust system in place from the second cat back it is still as quiet as stock at a cruise. Perfect.
I have a very minor teething problem at present with a VERY slight clearance issue on the overpipe (not uncommon with aftermarket overpipes looking at forum threads - there isn't much room) - but that's booked in to sort.
So would I recommend?
Manifold and remap as best bang for buck for an N/a car? Definitely.
Tuning Developments? Yes - they know what they're doing and on the basis of my experience they look after you. Added bonus - this set up can be a stepping stone to their turbo installation. Nice to have a decent specialist to look after us Northerners.
UEL manifold? Well... Results so far suggest that the EL manifold gets the best power gains by a few bhp, so take your pick. I wouldn't swap mine as I like the uneven Subaru burble and doubt you could tell any difference in power from the drivers seat, but if you're a sprint series warrior EL might be best on current evidence...
Hope this is of use to someone.
Sent from my iPhone using Tapatalk

Apart from the current issue, the supercharger is a fab bit of kit.  The integration and installation are very professional.  If I sit close to the front offside of the car I can just hear the intercooler pump swishing away when the ignition is on (I was pumping my tyres at the time).  Apart from that, the belt is nice and tight and runs true (I had problems with a previous Sprintex charger) and there are no signs of installation nasties.
On the road, at low speed I can just feel the effects of parasitic load on the engine but it's not a lot more than, say, turning on the aircon.  I guess it may become more evident in summer with the Harrop and aircon both loading the engine.  I need the mapping tweaked at low revs above idle to just help the fuelling a little for smoother control.
At speed, it's smooth, progressive and gives a hell of a burst of acceleration if I'm hoofing it.  3rd, 4th and 5th are the gears where you can really give it pedal and the rewards are eager torque right up to the red line (I set my light to come on at 7000 rpm).  It just feels like a bigger engine - no surprises, no suddenly coming on boost, just a linear shove in the back.  Even in the wet, it feels safe and controllable with no surprise snaps.  I like the way superchargers feel.
On the motorway, 6th is now a very useful gear and if I'm lazy I can keep up with most traffic without the need to drop to 5th.  If someone is pulling away, dropping it to 5th is usually plenty.
The car is noisier because of the effect of load on the sound and because I went with a UEL manifold.  With the TD super-resonator, it's as loud as I would want it.  There is no drone at speed but it can get loud on hard acceleration.
To my surprise, the 17 x 8 wheels with Michelin 225 PS4s are perfectly balanced for the car.  I really don't need more rubber, it's highly controllable and turns in well.
Overall, I am well pleased.  This is my daily driver and I needed it to work well.  You're always going to have some teething issues with boost and I accepted that as part of the deal.

Hi, I may have one or two. I will check it tonight, will let you know.
Greg.

That is because sixth is too overdriven, so you can't get to top speed in sixth. 

If you're looking to 'get into drifting' , I'd suggest buying a mk2 mx5 with a factory lsd and try that first rather than starting with a £15k - £25k gt86. 
If you do a UK drift day in your own car, you'll be mixing it with £500 bangers with welded diffs spinning left right and centre. You won't find many or any gt86s at public drift days. 
An alternative would be to do a drifting experience in a car provided to you. I help run Drift Limits in Hertfordshire and we have a good variety of cars to try out, from mx5's to V8 Silvias and a 1.2kilometre circuit with 1:1 tuition is provided. 
GT86's drift very well indeed of course but unless you have deep pockets, is not the best 'starter' car for someone who has no experience of drifting. 
In regards to the original question , personally I think you'd be mad to buy an auto over a manual for the purposes of getting into drifting. 
 

the top speed is only rated on 5th gear though

Manufacturers figures show 0-60 time slower on the auto and slower top speed...

At the end of the day it depends on how you drive your car and what you are going to use it for, if I could I would of bought a manual but did not have a choice. A lot of the comments made are true but I use auto on a daily basis and know how to get the best out of auto box.
It is a good auto box even compared to my BMW's all singing and dancing 8 speed. But the auto box can be frustrating pushing on when you want to hold a gear rather than change up or the reverse when wanting to use engine braking. So it's not necessarily the way it works it's the actual ratios which not matched to the engine etc.
I have changed the final drive ratio which has made a ton of driffence on drivability but you sacrifice a bit on fuel consumption. If the gearbox had better final drive from the get go then I would not of needed to do the mod.
Any auto box would be difficult to drift if you have not got the knowledge/experience on how to drift and as Lauren said go on drift school then decide.

As Keith said, the auto box is 'Ok' for a traditional manual, certainly a step up from manual boxes of 10 years ago, but with all the dual clutch boxes these days, the 86 auto is really sluggish. Manual shifting isn't immediate and isn't particularly smooth, and downshifts still feel like they're being done through jelly mounts. Perhaps I'm just a little spoiled as all I have to compare it to are good quality Mercedes autos, the DSG and a tiptronic in my old 911. The 911 gearbox was dreadful, so the 86 was a step up from that, but still light years away from a DSG or well sorted Mercedes auto.

Manual, more control. Clutch kick initiation, correcting drifts and probably cheaper to make more power due to the autobox. You'll probably shred through clutches. 

Something else to consider, if you plan on adding more power (serious power i.e. going force induction) then the auto box won't handle the heat and abuse of drifting the car or heavy track use.

He's saying the 86's gear box isn't as good as the DSG variants, I believe it's a very good auto box for a traditional gear box but still not upto DSG standards.

While you are pushing on I'd imagine not (especially if you plan on modifying the car i.e. changing the final drive, remap, exhaust system etc) but you will probably find quick starts off the line to be a lot slower than a manual, I can't remember the exact technical reasoning for this but I think it's something along the lines of the torque converter not engaging straight away thus allowing it to slip and preventing you from accelerating as hard as a manual gear box would off the line.

Yes as Deacon mentioned I drive a manual but I first test drove an auto but that was purely because that was all the dealer had. Maybe because I'm not used to it but found the paddles a lil fussy when driving normally and boring if driving in full auto. Paddles make sense when you're pushing hard or on track but you lose a lil fun in gear changing.

Forget the auto, it will be crap for drifting. Has to be a manual. 

If you want to drift is, manual really is the only way to go. Welcome to the forums by the way  

As others have said, unless there's a reason why you have to drive an auto, a manual is far better suited and you'll have better control of course. There are plenty of cars around, wait for a manual it's a no brainer. 
For drifting the lack of a clutch to kick isn't the issue. What will be an issue is, if you want to try and hold a drift and change up from second to third. The auto does not shift up quickly. You also won't be able to dip the clutch when you use the handbrake. Whilst you can pull the handbrake in an auto, it will disengage the torque converter, so when you get back on it, the response won't be quick enough. I think unless you are trying to prove a point, give up with the idea of drifting an auto. 

Keith drives a manual as do most of us. Whatever the intended use (fast road/track/drift) unless there are medical grounds I don't know why anyone would have the auto over the manual. The GT86 ethos suits a manual so much more.

It's not a dual clutch in this car

It's not dual clutch, it's pretty good for an auto but not as good as a dual clutch. I'd say wait for a manual, I'm assuming most of the autos that have been seen drifting on YouTube are big powered cars anyways which will be easier to break traction to start drifting, the 86 will require a bit more effort to achieve a proper drift and I think having a manual would be more suitable.

it will drop down a gear if your revs drop down to 1krpm or below which really is just for engine safety but it will just bounce of the limiter at the top end and will not upshift unless you tell it to
 
I've been sliding mine around, a clutch kick might've been useful once in a while but have had no issues initiating a drift without the clutch