One important advantage with Night Shift is that it doesn't mess up YouTube videos. I get weird artefacts with f.lux when watching videos, and overall Night Shift seems to perform slightly better as well. I'm sad for f.lux but for now I stopped using it.
edit: I don't get the artefacts with NS but I do get the same white border on the mouse cursor after watching a video full-screen for some time
edit: I don't get the artefacts with NS but I do get the same white border on the mouse cursor after watching a video full-screen for some time