I'm seeing a ton of various reviews on the Canon 6D, some loving it, and others giving it mediocre thoughts. I've been in the latter category and I really think that is where most of us should be.
Let's start with the good. It's not that the 6D takes a bad picture, it takes a great picture. In fact, it beat my 5D mark III in the low light test for example: http://www.learningcameras.com/reviews/4-dslrs/92-canon-6d-vs-5d-mark-iii.
But there really is no such thing as a new $2000 camera that doesn't take a great picture so I feel that it is not enough to rank a camera great just because it takes a great picture. There are a ton of great bodies under $2000 from various manufactures that can take stunning images. What makes a great camera these days is the ability to offer you the tools you need for the job you need it to do.
Given that...If you are a video shooter, I think you will be disappointed slightly. Not with the quality, but why the lack of a headphone jack that even the Nikon D600 has. Why no swivel screen. Why not dual card slots that the Nikon D600, D7000, D800 and Canon 5D3 all have.
If you are a pro photographer, you will probably exchange some profanity with the focus system (although the 5D2 was slightly worse), likely miss the joystick for quick focus point changes, hate missing custom buttons, curse the impossible to press DOF preview button that I love to program, hate the missing WB button and inability to program any other button to take this task over, never use it with a flash due to the slow 1/160 flash sync speeds, and desire a bunch of other curiously absent features.
If you are a casual photographer or want something for vacations, you will love this camera...if you can afford it. $2000 is a ton to spend on a vacation camera but you will enjoy the simple operation, great quality, and small size for a FF DSLR. However, if you were considering the Nikon D600, you will likely buy it instead given the pop up flash, dual card slots for overflow or backing up those vacation memories, and the Nikon ability to utilize the dynamic range in the shadows: http://learningcameras.com/reviews/4-dslrs/79-nikon-d600-vs-canon-5d-mark-iii-
Once again, the 6D took stunning photographs, even in low light (though the D600 is better in dynamic range by a long shot), but I just feel like Canon artificially limited random elements to make it compete less with other cameras rather than make it a great camera for an intended purpose, whatever that may be.
I've got a full review with samples : http://learningcameras.com/reviews/4-dslrs/91-canon-6d-review
Am I wrong?