Rotaries can be really decent motors, it just depends on the tune and built (just like any motor, but more emphasis on both with a 13B). A Renesis is an entirely different animal, though. When I used to work across the street from Mazda in Cool Springs, we'd see countless NEW RX-8's roll into the dealership on flatbeds (one, even, with a drive-out tag still on it!) because they were flooded, popped, or just plain wouldn't start. Fail.
With that being said, I'll take my 180,000 mile 2JZ-GE in my GS300, which uses no oil, leaks no oil, and runs like a top on plain old 5-30 cheap stuff...
or...
I'll take my GTE block in my Supra, which has survived countless 30/25/20psi pulls, 15psi HPDE sessions at 8,000RPM (and a missed downshift at 9,600RPM!), and asks for more. It, of course, doesn't burn or leak oil either...
I will agree with TJ, though - the 4AGE is one of the toughest motors ever built, stock. It's fucking reCOCKULOUS what you can put one through.