I'm looking at upgrading my mobo and the Asrock extreme3 looks pretty good on paper.
Are there any known flaws to this board and is a good choice?
Eh, looks pretty standard. A quick google search didn't turn up anything unusual. Seems pretty solid with the power delivery, only thing I might worry about is the BIOS, but that's because ASRock BIOSes and I dont see eye to eye. Never really liked the ones I've messed with, but then again I've never had too much experience.
I don't trust Asrock (because the only one I ever owned was really bad. e.g. it lost the mac address for the lan, bios settings and sometimes refused to even turn on), but they do seem to be improving greatly in quality lately.