Mazda rotary engines are highly reliable. If mistreated, the engine can burn it's seals and need a repair, but the engine can go for hundreds of thousands of miles. They get a bad rep because they eat a quart of oil normally between changes, and are far from fuel efficient by displacement. I think it was Road and Track that said " All the power of a V8, and the gas mileage too! "
The RX-8 has better CD than the RX7. 0.30 for the RX8, 0.33 for the 3rd generation RX7. But the RX7 has a better CdA, 6.14 VS 6.44
(Source http://ecomodder.com/wiki/index.php/Veh ... _Drag_List)
Oddly, those are both way better than the tiny Mazda Miata at CD 0.38 and CdA 6.68. For it's size, that's practically the aerodynamics of a brick wall. My 2005 Dodge Durango Looks like a brick wall, but it has a CD of 0.39, and a CdA of something in the mid 8s. Often what looks Aerodynamic to the eye isn't to the wind, and vice versa.
An old Honda CRX HF has a CD of 0.29, and a CdA of 5.39