I really like bios 601 and here of late I have been using 702. I actually scored my fastest pi time with 607 but for some odd reason that bios just did not feel right overall.
When I was running my Q6600 I really liked 502. Although as you can see from fatguy's post 702 is working well with the Q6600. I have tried as many mem sticks as I have different bios setups and I always
go back to my G.skill 6400 HZ (I have 10 Sticks of that). So there are a few different bios' that work well with this board!!

WZ