I use camera is a Canon, I know from 7 d to upgrade to the 6 d, upgraded by 5 d to 5 d2, upgrade 5 d3 again now, I feel 6 d is new. I used 5 d2, high iso noise big, slow shutter, focusing too slow, far worse than 5 d3. Choose cheaper 6 d, or directly to choose 5 d3. I don't know is there any help to you?
If I could buy a camera body for sure would take a Nikon D800, has a dynamic range of incredible color. If you already have a kit Canon lenses would definitely the 6D, see the tests and comparisons between the two models!
I have a 5d3, I don't think you can get a new 5d2 anymore. If you're going to manual focus all the time, I'd get the 6d to save money, the image quality should be about the same as the 5d3 for most stock photography. If you're using autofocus, the focus points on the 5d3 are brilliant. Manual focusing, 6d. Autofocusing, 5d3. By Xmas sales will be on so a 5d3 should be a bit cheaper but then again so should the 6d. Have fun choosing!
I have a 5D Mark II and I just love it. I do everything with it, from nature to family shots and even weddings. The Mark II is considered a professional camera and so many good things have been said on it. The 6D on the other end is more aimed at enthusiasts that want to go full frame. If you can find a Mark II (which I doubt, unless you get it used), the price will probably be very good so I would go for this one. If money is no problem to you, then go with the Mark III. The only ``problem`` when you go with these advanced cameras is that you kind of feel like it's an obligation to buy professional lenses. Because why put cheap lenses in front of a professional body? Then everytime you spend money on new equipment, you need to go deeper in your pockets! In conclusion, I would say go on the web and check out the reviews, it helps a lot. Good luck!
6D, no question about it. as low as 1899 U.S. dollars and it will be brand new with a full warranty ! I have tested it with the 70-200,, F2.8 lens and it is absolutely fantastic ! In fact, the 6D is on my wish list....
Lenses: Primes, L series and cinema lenses...