Errr I feel your pain. Some other guy on ASUS forums also got his board screwed.

I could flash to 0601 using EZ flash (from 0512).
It seems that some of the fsb holes I had are gone: at least I can go past POST more often, getting everything stable is another story.

I might not be the right person to assess 0601 improvements:
I have really had no luck with the parts I got for my nw rig: my QX9650 hardly goes above 3.6GHz (vcore 1.325V) and my brand new cellshocks do 1800MHz 8-7-6-21 1T only at vdimm 1.9V (1.7V gives me memtests errors), so no margin to overclock :-(