it will have trouble competing with the
Nikon D750 full frame dSLR and the old
Sony a7 II full frame mirrorless camera let alone it's forthcoming replacement, and if sport or hand held 4K video is your thing, then the similarly priced but much faster and more versatile
Olympus OM-D E-M1 mark II is a much better option, but if you already have loads of expensive pro Canon lenses, but can't afford a pro Canon dSLR, then this is a substantial step up from the old 6D except image quality disappointingly appears to be no better despite 5 yrs of years of technology!