I almost bought the Quadro FX 4800 but saw reviews where it was actually performing worse than the GTX 280 (I think I have the right model number) in key 3D applications and processes. I almost bought one despite the bad reviews but am glad that I didn't because I have heard that the 4800 was really a disappointment and expensive.
None of the Quadro cards have had optimised drivers. Not the 4500, the 5600 or the 4800. The 5600 and 4800 both used ever so slightly older, and thus slightly slower, GPUs than the consumer versions that were offered which accounted for the benchmarks.
I don't see why this card will be any different, I mean they are going to be making less money on this card per unit, why would there be investment in drivers now .
Anyone buying this card for purely for enhanced OS X application performance before independent benchmarks are out is silly.