So far it seems like the 3870x2 is the PPW champ. It also looks to be the PP$ (performance per dollar) champ.
Considering that the 8800Ultra is a money and energy hog, and lacks the VPU acceleration capabilities for video (HD, BluRay) the 3870x2 is a winner in my mind.
DriverHeaven.net also has a pretty good review of the x2 and it seems they received similar performance and stability upgrades with the later drivers, so I think SKY probably is right on the money with his review.
In addition, they discuss the lower minimum framerate on the x2, which by the way is something I've seen on my crossfire set up whether or not I was using 2x3870s or (like Tom's review) a 512MB 3850 with the 3870. I can tell you it does work which is cool, but not as fast as 2x3870's (but not much slower).
I think for the price and flexibility, the x2 will be tough to beat for a while. I consider it now a very viable solution for those who don't want to pony up $600+ for the 8800 Ultra, and have nVidia or single PCI-E x16/GPU motherboards but want the ultimate in currently available visuals.
I have a feeling nVidia hit a home run with the 8800 series, and the follow up may not be as exciting when the 9xxx series debuts later this quarter. And I'm no ATI/AMD fanboy, as I still love my 8800GTS, but love my 3870s more.
Regards,
10e