There's a general jankiness that I don't enjoy dealing with (especially when using high DPI screens), but the real dealbreaker for me is the lack of support by professional-level photo editing software. I personally use Capture One for most of my editing, and it won't run on Linux.
I can't speak to high DPI screens, but I've certainly had display issues out of the box. Usually they just required installing the right proprietary drivers (which surprisingly the graphics card company supplied).
Have you tried Raw Therapee or Darktable? I'm not sure how well they would work first-hand, but they sound promising for photo editing and might have some overlap with Capture One
