The onboard sound on the Rampage III Extreme was amazingly crap for such a high end board.
I waited for the X-Fi Titanium HD and got that along with some Corsair HS1As, and the setup is simply phenomenal when correctly setup.
I wish I had waited for the R3E black edition instead my current mobo and soundcard now though, as it has a top end Mobo and Soundcard bundled together for a great price for both.