It depends on how you ride and who you ask. How's that for a generic answer, I should have been a politician.
Personally I'm a recreational rider and I like the R&D, it's not a real aggressive intake grate, but it does a better job of keeping the pump loaded in mild to moderate wake it also seems to improve handling (I'm talking about over the stock grate).
If you're a more aggressive rider or a racer you might want to look into a Jet Dynamics grate.
Lou