Don't know what the WOW!! was for, but you've had quite a few STRONG!! recommendations for the 6D.
I buy and sell a lot... 20 years on eBay, photo gear mostly. Nikon and Canon, at the same time, both tried to break the $2000 price barrier on FF, so I immediately looked for the problems that would "tank" resale.
With the Nikon, it was the "self oiling sensor" (bad shutters) many replaced by the 610 and well over a year to work it out. With the Canon it was the filtering on the video, as Canon has been reluctant to let go of AA filtering, which cost them resale.
This happens all to often. I venture that everyone who vouched for the 6D has only used it for still and has not done much video wize or quality wise professionally. This video problem did not take long to find. It became an issue when the camera hit the market. Fixes have been spendy.
Or just don't shoot other than mediochre video.
There are really two ways to research your equipment and software. A Forum like this will work somewhat, but you will get PASSIONATE BAD ADVICE along with the good. 50/50
Or go to the pro review sites and read, read, read and look at pix from the gear you are interested in. Two great sites are Steves-Digicams, and DPreview. There are others, but those to are exhaustive.
I wish you luck in your search.
BTW, I myself have owned one Full Frame camera. I have been shooting film since the sixties and digital since1993 and DSLR since 2003. Been through ton of camera's.
Other than the one FF camera, I have not encountered anything I can't do with a DX or 4:3 camera. I shoot a wide variety of subject and format including film in medium format, and large format. In fact, buying one now.
I conclude that I in my trade must shop for resale first. I conclude that those who are prone to change gear often for the latest and the greatest must also pay attention to resale first, then all the other stuff. If it has bite marks on the early reviews.....
scratch it off the list now and permanently.