MSI boards are great; I have 3. (KT3 Ultra-ARU, K7T266 Pro2 and a K7T Turbo.) One of their strongest features, IMHO, is the ease with which you can update the bios, drivers, etc.
I use the KT3 Ultra-ARU on my system. It's extremely stable and I can overclock my Athlon XP 1900+ to 1.76GHzt. It does have USB 2.0. The only drawback I've encountered so far is that it doesn't support separate IDE devices on channels 3 and 4. It supports RAID only at this point. However, my understanding is that this will change with a future bios release.