In my opinion, i would take the Asus over MSI any day of the week. I dislike MSI due to their horrendous bios department. Instead of spending the time to get a decent bios done right, they release a mobo with a barely working bios and then spend the next year trying to fix the problems via bios updates. It is one thing to have several bios updates on a board over a years time when there are lots of changes being made specifically new cpu support, but MSI has close to 30 bios updates for a single mobo in only 9 months time. I got burned by MSI back in the day and they have yet to come close to winning me back. The only way i would ever buy an MSI board is if my only other choices were ECS and PCChips.
Asus boards for AM3 have been rock solid and very dependable. Sure you pay a premium for that, but that little bit extra is so much worth it vs the hours-weeks of frustration that can be had making a finiky board stable.