Sony A7R new, seen at B+H photo, and D600 is not a D610, can be found in mint condition for $1100. That's where my dollar number comes from
I am not going to start a camera discussion here. These things go on forever and don't really give any advice to somebody not sure about what they should bring on a backcountry trip.
Obviously, if you have $2000+ to blow on a lightweight camera with hiking being the only thing you care about, go for it. I know very few people who are serious enough about photography and ONLY care about the use of the gear in the backcountry. Once you add uses of that tool that go beyond bringing it up to the top of Whitney, the weight advantage loses even more of its attraction.
I also shoot cars - when a 14 pound lens is mounted, the camera body works a lot better when it is large and solid to allow me to hold and pan that glass - 600mm f/4 handheld:
Maybe this also explains why I think 12 pounds of camera gear in a 50 pound backpack is "going light" from my point of view
