I've been using v1.6 since not long after its release and have found it to be the most stable of all the BIOS's, both official and the OCW betas.
The only problem I had was sometimes it wouldn't boot, but this was solved by changing the new BIOS option "AGP P2P Deep Fifo" from the default of Auto to Disabled. Having an AGP ATI card, and this option is for Nvidia AGP cards, I'm assuming by default this is enabled and that was the cause of the problem.
As per my sig, I'm running with the HTT set to the max this BIOS will go to on 1.4v. My HT is set to 600(x3) on both buses to keep it below the 1Gb mark.
With regards to memory, I'm having the same problem as a lot of other users in that I'm not running at 1T. It's stable within windows on 1T(prime stable, OCCT, SnM, Aquamark, 3DMark05 and Super Pi)but fails memtest test #8 pretty well straight away, so I run at 2T to be on the safe side.
HTH Mrchu_, dagwoood.