I second that, fantastic looking board. Couldn't believe the quality on the heatsinks, really really nice. Having one problem though, and that it that my Logitech G510 doesn't seem to want to work in the bios, should be fixed in a bios update though I guess.
With your USB problem make sure it’s in a 2.0 port and check that (legacy USB support) is enabled in bios, I had problems with my Extreme4 board it would stop on bios screen with an error code every time I started the PC, but it was just the mouse been unsupported for some reason, The only thing I could do was disable legacy support and the computer would boot fine but then the keyboard wouldn’t work in bios then (Logitech G15) So I’m just thinking it could be the other way round for you..