5D looking to upgrade, but indecisive..looking for feedback

If I were you, I would go into a camera store with a couple of Flash cards and try out different systems, You can then check the results conveniently in your own time.

I tried the Canon 5d mk3 with the new 24-70mm 2 and a 50mm 1.2  and the Nikon d800/e with equivalent lenses. I opted for the Canon but that was my personal preference according to my criteria! I shoot Portrait and Fashion.