I sure have made that change @sduk there's no doubt that the D850 is a better camera than the D750, but it's not a massive difference. When I changed from the APS-C Sony A77-II to the D750 I was blown away by the D750, not only in terms of functionality but also with the images I got from it. They had better colour, better pop, better depth and way less noise. I didn't get this same wow factor swapping from the D750 to the D850. That being said I don't regret the change, the reason for not getting the wow factor is that the D750 is so good it's difficult to be truly wowed after that IMO, at least currently. The improvements of the D850 are small, but over all they do add up to a lot. I do actually prefer the colours and colour accuracy from the D850, the build is better, the detail/sharpness is crazy (combination of resolution and lack of AA filter), the extra resolution helps with cropping for wildlife, the illuminated buttons are useful, and the extra buffer size is really handy for me for sports. Oh and the viewfinder, it's noticeably bigger and nicer to use. The negatives are the extra weight, file size (although I've not found this much of an issue), and noise handling isn't as good. That being said, I get useable images at ISO 12800 without needing much NR. As for the shutter count, it shouldn't be reset (Nikon UK say that the shutter count is a reflection of the overall use not just shutter) but there have been a couple of cases where the shutter count has been reset, not sure why.