I have no experience with the PDB-R, but.....
I've been running 2 P3 700's in a Rioworks PDVIA that I picked up off of Ubid for ~$50. It's been batting a thousand in the stability department. Even though it's a VIA chipset, there's been no compatability problems, no lockups, nothing. It's really a quality board.
A few complaints I have are:
1) No voltage adjustments for overclocking the cpu's. With the latest BIOS, they have FSB settings up to 150 (I think). The 700's I have can both do over a gig, but they're slot 1's, so I don't have the benefit of upping the voltage with a slotket.
2) The cpu slots themselves are extremely close together. The cooler I have on cpu2 sucks, and there's not much I can do about it because nothing that's any good will fit.
3) I can't think of anything else.
Hope this helps you in your decision.