I drove the RX8 with a friend last year. It's definitely a nice car, I especially like the two tone interior (red/black), its probably the best color combo (and I'm glad I have it in my car).
I really love the center console in the RX8, it looks cool, the design is wicked and I like the 'piano black' type finish. I also like how the handbrake looks like the handle of a sword or something like that
My friend has an M3 (E46) and he said that the handling of the RX8 was pretty much on par with the M3 (he's crazy with cars, really knows how to navigate turns at high speeds, I was freaked when sitting in the car while he was driving, haha).
Only problem we had was the quality of the brakes, but it's not quire fair to compare them to the ones in the M3 (much more expensive car).
Good buy *thumbs up*