if ATI are using xfire to get a win i really hope there are no issues.
and that it works in a vast majority of games
but the question is.. how much faster in almost all recent and not so recent games?
we already know the new cards will be killers in source games
The 3870X2 was (and is) a really nice solution.
I didn't experience any serious issues with it during my ownership (except one that was down to a faulty motherboard).
All games ran brilliantly, and at full speed.
I had more issues with my 8800GT than I did with the X2. I'd say ATi have this kind of thing down to a tee.