I just did a similar decision process and went with the 6D.
One feature that is really great with the 6D and the 70D is that you can control them from a phone or tablet via wifi. I shoot a lot of HDR and architectural interior shots, and being able to set the camera on a tripod, then see a live image on the phone, and do total shooting control remotely is a godsend. No more having to worry about getting behind the camera in tight locations, carrying a right angle finder and a remote release, etc. I really don't understand why the wifi control doesn't get mentioned much in reviews and so forth.
I'd say the image improvement over the 7D I used to use is pretty significant too, especially if you print 13X19 or larger.