OK, double post.. But I feel it's somewhat worthy.
The 1.55Beta is NOT a machine killer (thank Cod!)
I haven't really had time to to play with it, but at least on my machine it hasn't caused any major problems (see Sig). 1066 Mem mode still works quite well... (you still need to tweak timings).
Guess the only real info I have on this Beta Bios is... It shouldn't kill your board or chip (which is a good thing

)
Just my brief testing, but it seems to have decent potential.
Here's a SS using 1.55 Beta:
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