The image quality, thankfully, is as good as we'd been led to believe, delivering the huge megapixel count of Sony's A900 and matches the clean images of Nikon's D700, both scoring 2.0 in Pop Photo's noise test at ISO 6400. In other words, "Such high resolution and ISOs will change your photography." Video footage is "beautiful" (though we already knew that).
The bad? The most crippling issue is that its autofocus system is sloooow, lagging way behind the D700 and A900, and it's even worse in low light. Pop Photo also encountered the notorious black botches plaguing some of the camera's shots with blown-out highlights, but they suspect it'll be fixed with a firmware update.
Their bottom line is that "it's a wow" and "low-light image quality is almost life-changing." Even if you already own a 5D, you gain on almost every front, so it's a "perhaps irresistible" upgrade. Be sure to check out the full review: [Pop Photo]