For my setup it is not so good. Definitely worse than before patching.
Update:
Interesting, after I disabled the crossfire my FPS doubled and stutters significantly diminished.
New problem became on/off blinking of exterior plane texture. Plane textures would disappear and you can see the pilot inside the plane.
Definite crossfire issues.
Update:
ATI CrossFire Users - see the following post for a possible solution:
http://forum.1cpublishing.eu/showthread.php?t=31805
With this tweak I am seeing ~75% improvement in FPS and a significant reduction of stuttering.