How does it do against its more-expensive rivals? The A850 certainly has the edge in resolving power over Nikon's 12.1MP D700 ($2,700 street, body only), as well as the 21.1MP Canon EOS 5D Mark II ($2,700, street, body only).
But both of those top out at ISO 25,600, and serve up less noise at ISO 6400 than the A850 does at ISO 3200. In the D700's case, it showed less noise at ISO 12,800 than the A850 did at ISO 6400. So committed low-light shooters would probably be happier with the Canon or Nikon.
All three scored Excellent in color accuracy, with Canon coming out best. In AF speed, the Sony outperformed the Nikon in all but the dimmest light levels, with the Canon trailing both.
The 5D Mark II, however, has full 1920x1080p video recording, while neither the Sony nor Nikon record video at all. The Sony doesn't even offer live view, instead providing a still preview that displays changes to settings such as exposure compensation and white balance.
Sony seems to have found just the right tradeoffs to create a compelling DSLR. While any of the compromises might make a difference in some situations, together they seem like only minor quirks in the face of the A850's significant price reduction, big wideangle views, and huge pixel count-in short, a thrilling fullframe experience.