As long as seeing correct color is not important to you. I'm the kind of person who can immediately tell when an LCD is not at native resolution and what temperature the color is set at, so the strong yellow tint of f.lux was unbearable.
If your eyes hurt at night, just alter your brightness contrast, or write a script to do that instead of messing with color!
Me too. I am very sensitive to what's going on my screen. Even though it takes hours to transition, you can tell. And I love it. Flux is brilliant. It's also generally easier to wind down your brain toward the end of the day. It's not easy to sleep soon after staring at high temperatures.
Why not mess with colour? I have no need to see the 'correct' colour, if it's less comfortable to me.
I actually leave my LCDs at a redder tint most of the time now, as I find it more comfortable. This is particularly useful as most desktop LCDs won't adjust their brightness down far enough for me. Laptops are better, since they actually bother to adjust the power of their backlight.