Really? With JUST a tune the GTI will be quicker than a stock 2010 MS3?
I don't know enough about it to make "intelligent" comments, but I would suggest looking into this more carefully before just assuming that this magic tune is going to be the end-all perfect answer to the stock GTI's serious power deficiency. There may be some issues / aspects that will not be desirable. If you want to be safe, I'd recommend finding a GTI owner that has had this exact tune done, and see if you can go for a ride in that car and interview the owner etc.... an unbiased guy, not the friend of the guy doing the tuning.
In my opinion, the 2010 MS3 is just barely "fast enough". This is not to suggest that it's not fast, but... I think if it was any "slower", I'd be unhappy with it. It's right on the line. Based on the C&D review, if the stock GTI is indeed considerably slower / less torque etc, I personally couldn't live with it under any circumstances. If power is important to you, you may wish to give this all a lot of thought, because if the magic tune you speak of doesn't work out the way you hope, you may be stuck with a car that is grossly underpowered... and you may be miserable.
What was really important for me was to be able to test drive a brand new bone stock MS3, decide I was satisfied with the power / performance, and then be able to buy the exact car with exact performance. No guess work, no hopes, no depending on a magic "fix" to make the car perform adequately, etc. I personally would not have wanted to take that risk.
Maybe power / performance is not AS important to you as the interior etc, that's fine... we all have different values / goals... but if power IS important to you, I'd think twice about buying an underpowered car and then hoping you can bump up the power via the promise of a magic tune or whatever. I'm sure the tune will help, but it might not truly provide what you're expecting.
If power IS important to you, you might want to just consider going with the new MS3 which will definitely give you well dialed in factory power out of the box with appropriate torque management etc... there's no better way to have it. You need not touch the car, and it'll be ready, right off the showroom floor, to blow the doors off any stock GTI or almost any other car in its class. It's a nice thing to be able to buy a car that is ready to perform, right off the showroom floor.
Funny, ever since I read that C&D comparison test, I've noticed a lot more new GTIs on the road (because I'm just more aware of them now)... and EVERY time I see one, it's always in my rear view mirror, slowly disappearing... makes sense. They don't even try to keep up. It's kind cool driving a car that's so intimidating, with the guts to back it up.
Well, best of luck with your decision in any case. Yeah, the MS3 interior is perhaps not the "finest" interior on the planet, but it's surely not as bad as a lot of you guys suggest. For my purposes anyway, it's way more than adequate, I'm 100% happy with it... especially considering what I paid for the car. But I'll admit, power is more important to me than interior refinement. Quite honestly, when I went to see the MS3 for the first time and saw the price, I expected way worse in terms of both power and the interior... but of course, as we all know here, for the money the MS3 gives you loads of power and an interior that is at the very least above "adequate". It does NOT suck. It's fine. It ain't the best, but it's fine. Would I trade power for more interior refinement? NO WAY. That's just me.
(drive2)