Yeah, it's sorted
Yeah, the RAM freezing issue was fixed in the firmware upgrade a week or so back. I was getting intermittent freezes with 4GB Crucial RAM before, now it's stable. It's nice having a computer which I can trust not to shred everything I'm working on at random intervals.
I was disappointed though when the MacBook failed to wake from sleep properly the other day - it seems that issue is still unresolved. Only happens very rarely, but still absolutely unacceptable.