Do you already have a Canon 60d and have you invested in Canon lenses and flashes?
If so, the 6D is probably the obvious choice.
I had a 6D and absolutely loved it, although the focussing system is far behind the 5d3.
Personally, I'm not interested in Sony mirrorless cameras. I like the fast focussing and ergonomics of DSLRs, as well as the great amount of accessories available. (Canon/Nikon)
If you are considering changing systems, surely you've considered a used Nikon d800 or new d750?
Both offer excellent bang for your buck.