Haven't owned one, but have driven a 997.1 GT3 RS several times - it's of the same nature as the NSX, power and limits are higher, and it's a bit stiffer and slightly more nervous all around than a stock NSX, but they're both fairly simple/elemental cars. I prefer the NSX because it's "slower" and I can enjoy the car more on public streets. If you're at the track all the time and you're a good driver, then you'd be able to take advantage of what the GT3 has to offer. After driving the GT3 I found that I could hardly enjoy the power band on the street because it's so dang fast - if I owned one I'd either be A) frustrated all the time or B) in jail. A turbo would be even worse!