This or that?

[CMPhotos]

Hello everyone. I am looking for a new camera body but can't decide on which one. I am currently working with a 40D and like it a lot but would like an upgrade. Considering a 7D or 6D as my next body. I have been thinking on this a while but would like some input from anyone that has used these bodies.
My thoughts are that I like the AF system in the 7D with the 19 cross type points and that I can use all my current CF cards. I like that the 6D is full frame and has wifi and the high ISO settings. I already have good lenses 50 f1.4, Canon 24-70 f2.8L, Canon 70-200 f2.8L IS II, Tamron 17-50 f2.8 (I know I can't use the Tamron on the 6D so another pro for the 7D). The 40D will become my backup body. I am also on a budget or I would get a 5D MkIII. Thought not able to afford either body right now (I only have about $800 saved up) I want to have a plan for when I go to buy.

 

[goodguy]

I just dont see any comparison between the 2 cameras.
The 7D is an old camera and while still capable its age shows.
The 7D only merit is only if you plan on doing mostly sports shooting, yes its AF system is better but again unless you are planing to do serious sport shooting the 6D is simply MUCH better in every way.
The list of advantages is too long to start, if you can afford the 6D then get it!
I personally think crop sensor DSLR days are numbered and in the future you will see mostly FF DSLR but that's my guess so take that with a grain of salt.
I have 51 point AF camera and I use 99% of the time the centre spot so I wouldn't worry too much on the 6D less sophisticated AF system.
As you said its low light performance is far better then the 7D and I believe so does its focusing system in low light.