The 5850 has DX11 support, so there's no contest, really.
It is more powerful than the 285 anyway, it pretty much beats it on all things non-folding.
EDIT: lol, i voted for the 285 by accident (instinctive nvidia fanboy habit), i meant to vote ATI.

It is more powerful than the 285 anyway, it pretty much beats it on all things non-folding.
EDIT: lol, i voted for the 285 by accident (instinctive nvidia fanboy habit), i meant to vote ATI.