I've been on the fence about switching out my gear for quite awhile now. I've got a Sony mirrorless rx10 iv which is good for an outdoor walk-around bridge camera which I will keep, Nikon P950 for the extra reach of a long zoom and my Nikon D500. I finally decided to go completely mirrorless and am going to get rid of the two cameras and lenses except the sony. It makes me nervous b/c I've had a love affair with my d500 for a long time but it's time to break up. Portability is a factor b/c of the long hikes I go on and carrying around a big DSLR and a 500 mm lens is very heavy. I need a lighter system. I'm looking at a full frame mirrorless sony (might get a good deal on a used one) or possibly a nikon. Anyone got one and have any pros and cons to share? The used one I'm looking at is a sony a7r iv but if that doesn't work out, maybe an a7 iv (more reasonably priced) or nikon z7 ii. Thoughts? Advice?