I have had a TT 6sp supra running around 480bhp, it was a handful!!!! Awesome car, but the slightest hint of rain and its ass was everywhere! The TT engine is silly strong, same as the gearbox, but the weight distribution is not that good compared to the Z. Own a Z now, it might be the fact that its less power, but I do prefer it.
I disliked the s2000 when I test drove, felt very claustrophobic with the roof up and disliked having to rev the hell out of it to get it go.