The Porsche TT, X50 or not can be tuned to well over 700hp by software, waste gates, boost and other stuff. I don't have the X50, but the German auto specialist that maintains mine offered 120hp for about $3500. Thats 415 + 120, not too shabby. Along with that awd, active suspension, et. al., it's not nearly as difficult to drive. With my tiptronic, I never worry about hooking up or when to shift. Too simple. For the same money we put in our Vipers, i.e. $25K+, the Porsche becomes a f'n monster. I'm sure the guys at the P board know all about what trick stuff there is for them. Respect. Porsche has always delivered much less than it's capable of for production vehicles. I'm sure reliability enters the picture, also. I have always enjoyed my Porsches and will continue to do so.
I'd rather keep mod'ing my Viper, not as technical and electronically sophisticated, more fun to drive, looks and sound more aggressive and most of the time that's all that is needed.