When high Sierra was first released I was warned against it due to it causing some serious performance issues, I can’t remember exactly what but something’s niggling away saying it was something to do with the GPU possibly? Anyway, have all issues been resolved or are there still problems with high Sierra? I have the touch bar 15” MBP. I don’t have any issues with Sierra so I’m not desperate to upgrade, but it’s just that I’ve just bought the Nikon D850 camera and Sierra does not support the RAW files, yet high Sierra does. I don’t know if high Sierra gets preference, or whether it means that there won’t be support for the D850 with Sierra? Anyway, any advice appreciated.