GT3 and e92 m3 are two very different cars. M3 is great, I love it, but it's still a relatively heavy car. The GT3 on the other hand, wow.... knocks my socks off (and then some) every time I get it in... If you don't need the seats in the back then it's easily got to be the GT3 over the M3... Just my 2 cents

 

GT3 is the best driving experience. I hate driving anything else! But then again, I am biased!