Here's the thing. Everyone is coming into this thread already knowing that the 5D mark III is the better overall camera. But what I'm also seeing is people who need to justify their purchases again, and that's where all the flaming starts. The truth is, the 6D is a great full frame camera to build on, but it's not that far down below the 5D mark III, especially for normal use. The uneducated folks in this forum seem to use the word "rebelized" (a term which only applies to Americans, really) a lot, and probably never even used a rebel much less a 6D to actually feel and shoot photos with them to know the difference. Another misconception I notice is the justification of the 6D sensor being incrementally better. What is unknown to both DXO and someone who hasn't shot photos with both, is that the difference is barely if not at all seen in real world results. Fact is, the 5D mark III will always produce more keepers in some specific shooting conditions, and IQ is more than just nailing one good photo. IQ is also about nailing good photos all the time. And that's the main reason why people put the 6D down, not throwing into account that the 6D in general purpose will at least do more than half of the 5D mark III's job just as good. I.e if you're a landscape or macro/portrait shooter you will very rarely need the higher AF performance and will make up for it in a big way with its more robust, low noise, full frame sensor. That said, the 6D is doing quite well picking up from where the 5D mark II left off and the 5D mark III is a very good next generation camera.
Very well said.
In thinking about it, I guess there's really just a few important questions (and these questions will change depending upon your personal use and need). Here's what I think (IMO) are a few of those questions...
1. Can I afford this camera? (And does it offer ME value?)
2. Will I use this camera? (And then, will I use it as the tool it's designed to be utilized as? )
3. Will I be pleased with the results that come from this camera? (Note that this is also a function of understanding your own skill level - lot's of people are perfectly pleased with P&S camera results).
4. If this is related to my work/business, can I make money with this camera's results?
5. And, probably my favorite question, Will I have fun shooting this thing?!
There may be more, but in essence, that's really what's important. I bet a lot of 6D, 5D III, and other model's owners can all answer a resounding YES to those questions. I ask myself these questions for my camera's, my A/V equipment, and my car. Gotta be fun though - that's a deal killer.