[Brightcolours]

I never really "dig" that "struggles with XXmp", because usually that only "goes" for borders and corners to some extent. There are many lenses that do well (enough) for high res. entire frames, and usually the center is where the main subject is so the slight drop in borders is not that apparent. Also... Same as with all features, you don't need them for every shot. So, you might have two high resolving lenses for shots that need the higher MP/bigger print size, and for other shots any lens will do just fine. So, with a higher res. sensor you never get worse resolution results, and often better ones.

61mp is only 30% higher resolution than the 36mp D810, and only 16% than the 45mp D810... 60mp may sound like a big jump, but "mp" is an area measurement, not a resolution measurement (resolution is the width in pixels, or the height in pixels for instance).