I upgraded from the Rebel XTi to the 6D about a year ago, primarily because I outgrew the XTi and needed a camera that could do more. A few months after upgrading, my XTi got wet and died during a trip to Iceland so I've been looking for a 2nd camera body for my wife.
A little about my shooting style, I mostly shoot landscapes, night photography and portraits (also macro but not as much). My wife and I travel a lot, so street photography (and low light) is also part of our shooting style. I do events every now and then, but it's not my focus and is usually done at the request of family/friends. I can't say I don't like shooting fast action (sports)/wildlife because I've never really tried (I'm sure if I did I would like doing that as well). If you're interested to see photos, click here: http://www.flickr.com/photos/97429425@N05/
A little about my gear, I have a 35L, 17-40L, 100L macro, and the 24-105L (which I'm going to sell to help pay for this new body). The 35L was the last lens I bought, and I realized I liked shooting with primes over zooms. My wife is the opposite, she likes the versatility of zooms.
Anyway, I'm down to 3 different cameras, the 70d, 5D Mark iii, or another 6d. Price is definitely a consideration, but I'd rather spend a little more (or a lot) to get the right camera. I've looked at enough spec reviews and sample photos to know the difference among all 3 cameras. My shooting style screams 6d (and the fact that I really love my current 6d), however my wife's shooting style is suited more for the 70d. She really wants the rotating screen, and I think the new touch screen focus system of the 70d is a major advantage. Also, she isn't into learning the technical side of photography as I am, so having a 70d that has a few advanced features but is simple to use is also a plus. I think the 7fps of the 70d would only get used every once in a great while. For me the 5diii is still under consideration (in that case, my wife would use my 6d), but it does cost an arm and a leg. I'm not going to get into the 5diii specs, but there are times when I'm shooting where I could benefit from some of the 5diii's capabilities.
That being said, I was interested in getting user opinions on real world shooting, not a spec comparison. Thanks ahead of time for your thoughts!