I don't think so...
For all the hassle of selling your camera and buying one that has a lesser build quality....AND paying the extra difference, why not just buy a T3i for the 720 60P and as a back up body/B camera to your Mark 2
I always wanted a FF camera and I had high hopes about the 6D, thinking that it would be identical to the 5DIII in video, but the recent reviews showed that it suffers frome moire...
Although I dont consider moire to be as huge problem as other people think, I would prefer if it wasnt there! Especially when I know from the MK3 that it is possible!
Now I just hope that 6D will be identical to the MK3 at high ISO...if its not, there is no reason for me to upgrade from what I already have (60D, 600D).
FF is nice of course, so I might just save for the MK3...
the 5dii has moire too...it's also not a big problem for me either as it is for others...I've filmed with all kinds of cameras and DSLRs (including the GH1/2, T2i/3), but ever since I started with the FF, I could never see myself going back to a smaller sensor...I really didn't understand it before, but there is something about the FF that just gives off a different look/feeling...at least IMO