Let us know what you end up with. I love drooling over other guys' toys...
There always seems to be the same guy with a Bushmaster .50 at the range when we're there, I've only spoken casually with him but FWIW he's definitely happy with his, but I don't know the specifics.
I do know...we keep several benches away when he's shooting
Serbu's are made locally to me, and we see them fairly regularly. Most comments are positive as an "entry level" .50, but from what I've heard you get, what you pay for, in the accuracy dept.