My dad bought one as a retirement present for himself, I have driven it on several occasions and I love that car. The engine is smooth as silk, it has ample power, and the engineering is incredible. The car corners like it's on rails no matter what the speed and no matter how hard I have pushed it the RX-8 always feels like it's saying, "Just a little more, just a little harder, just a little faster." My dad says that he has only gotten the traction control to kick in once on the road, and that it lets you do a hell of a lot before you get to that point. The traction control apparently kicks in shortly after the driver empties his bowels into his trousers, so all of you guys who like going balls-out with no computer aids will love it. The fact is that the car is so well designed that it doesn't NEED computer aids, it has a ton of grip that goes on forever.
I especially like the car in the mountain roads where piston cars are running the gears from 1 to 3. The RX-8, because of the long powerband, can stay in second the whole time so you can be constantly on the power. My dad has several stories of dumping Porsches, Audi quattros, Nissan 350Zs and a whole assortment of other cars - usually at the first tight corner. One Audi nearly ate the guardrail trying to keep up.
As for the alleged "problems" of the car, there has been one recall. It constituted changing the spark plugs and updating the fuel management software. That's it. Many of the "piston heads," as my dad calls them, took the chance to bash the car. I heard all kinds of stuff, including that they were going to have to replace the engine in every RX-8 on the road. What Mazda did say was that in some rare circumstances, if the car has been aggressively raced for most of it's life there was the chance that engine damage could occur, and if necessary Mazda would replace the engine at no cost to the owner. To the best of my knowledge, no RX-8 engine has needed to be replaced because of the recall. This press release was not an impeachment of the car, but rather Mazda standing by their customers no matter what it took to fix the problem. When my dad took his in to have the work done, the dealership gave him a free rental car (even though it only took a couple hours) and they filled up the tank for him.
I love the RX-8, and if I had the means I would buy one in a heartbeat. I am not as impressed with the 350Z, the ride seems worse than the RX-8, but it's slower in the corners. It's faster in a drag race, but at the first sign of a bend the RX-8 makes up for it's lower bhp by taking all the speed through the corner. I have driven both the 350Z and the RX-8, and while the 350Z has more power, the RX-8 is more fun to drive. The Nissan seems crude and cumbersome by comparison.