Now non-fluxed monitors at night somehow feel rude to me. Like someone waving a flashlight in my face.
I have never used such kind of software but I feel the same rude way about my screens at night. It's unnatural to get that strong light pushed into your face at late hours, even if you have experienced it for years already.
I agree that the shift towards red light on your monitor is weird at first but after a short while you get used to it, and your monitor starts to look very weird without it.