I think there is quite a difference between the N/A and TT to be honest and it sounds like your a man that likes his BHP otherwise you wouldnt be considering a TT. Both in standard trim the TT is obviously going to be a faster car, it has about 100bhp more but the advantage of the TT is that BPU will see you close to the 400bhp mark for roughly £1300 (less if you get second hand parts) thats nearly twice the power of the N/A. Also if you are into quick cars then remember that there are plenty small hatches out there with about 200bhp, Civic type R, Clio, celica's, integra's etc that a N/A would probably be matched with. When I went to look at a supra I took a N/A for a drive and then the TT and after the drive in the TT there was no way I could buy a N/A you just get addicted to the power and then when you get used to it and you want more there's always BPU but the N/A cant really be modded power wise unless you slap a turbo on it, which aint cheap.