Well, i learned how to live with it. I stop shooting in 720p. Now only at 1080p, with cinestyle picture profile, witch helps a lot, with sharpnes all way down, and low contrast. Aliasing i comon 6d problem. If you see aliasing on screen while shooting, change position or try to make that spot to be cover with bokeh. Right now i am switching to GH4. Gives me 4k video, now aliasing and moire, becouse it have antialiasing filter, but no soft image like 5dmk3.
Hope i help a bit.