I've been using the Epox EP-8KDA3J for about a month now. It does have under voltage problem, I just raise the voltage..prob solved. It is pretty picky about ram, and Cool & Quiet dosen't work with 2 dimms.
Other than that it's a nice board, all the OC options in the bios.
that being said, I just installexd a ASRock K8S8X SIS755 chipset board about 6 hours ago.
I must say that my first impressions are very favorable. I get a better OC on my Clawhammer 3200 with just 1.475V than I did with 1.75V on the Epox. I'm not a real big OCer anyway, at least not with the A64 rig, now the NF2 boards and mobile XPs are a diff matter.
Very stable, I've been trying to crash it since I installed it and no luck so far. It took any combination of pc3200 that I had with no complaints.
The bios lack some of the setting that the Epox has such as VDIMM adjustments, but it seems to be fine with the default settings. It is prob a bit early to make the the call just yet, but I think I like it better than the Epox.
the upside is that the ASRock board is cheap.