I think you'd see a lot more RX8s around if they had a version with the 2.3 turbo.
It just wouldn't be the same car mmret. It's the rotary's size that allows the car to be as dynamically balanced as it is.
That said, I've experienced first hand how buggy these things are. Buy one of these second hand - and have access to a second car.
Saying that, I'd take the RX-8 over the G37 anyday..."the people that get it, are really more into enthusiast driving". Sorry Railton!
The quirkiness of the rotary is the thing that turns me off about the car. For Mazda being so practically minded (the mini doors, back seats, IIRC decent storage space), selling it with an engine that sucks gas like no tomorrow, burns gobs of oil, has questionable reliability, and produces about as much torque as a base Civic doesn't make sense IMHO. Its the engine that takes an otherwise great car and adds just enough annoyance that I wouldn't buy it.
Now, some people want this engine in this car. Fine. I'm just asking for a variation. They already make a good 2.3 turbo. Surely it can't be that hard to bolt it into the RX8 and surely it is not THAT heavy.