Planning on getting some
1.9v DDR2 SDRAM Unbuffered DDR2 675 (PC2 5400)
along with a C2D e6600
with a 7900GT KO gfx card.
no need for oc'ing, just want a good board.
opinions
What features do you need? P5B has more of them (I'm assuming you mean the P5B Deluxe btw...don't see much point in using the non-deluxe):
RAID-5 support
dual gigabit ethernet
integrated wireless
e-SATA
firewire
...and the P5B also has more of the standard things:
7x internal SATA vs. 6x on the DS3
ADI audio instead of Realtek
...but, the P5B is also $60 more expensive on newegg right now. If you need any of those extra features, it's a reasonable price to pay (especially if you peice it out, and add up what you'd have to pay to put a second ethernet card, a wireless card, a firewire card, and a RAID controller card into the DS3), though conversely if you'll never use any of them, it's a rather large premium.