i need to check my kidneys and if both are ok, i need to sell one and buy Canon R5 :D

on a serious note :D i am still on crop sensor of Canon 80D and am thinking of going full frame. And with new specs that are pushed into mirrorless i think manufacturers are trying to push the industry to it. I feel it would be crazy for me to buy 5D IV with the specs of R5. Also i would need lenses for full frame.

I am not that familiar with Nikon lenses but future proofing sounds as a smart thing to do. Buying lenses with new mount sounds like a smart thing to do.

had an oportunity to work with Sony (forgot the mark, it was full frame) and with Zeiss 35mm 2.8 it is really compact. Maybe even to small for my taste. if you hold you camera for few hours good grip could be really important, if you take photo and than walk 40 minutes to take next photo, it is probably better to be compact :D

i did not help you, but i feel your pain :D