[kumaraman]

Using location is more accurate as depending on how far away from the equator you are light levels can change drastically.

This covers some of the details around it: http://www.ccfg.org.uk/conferences/downloads/P_Burgess.pdf

[adt2bt]

I think the gist isn't to match the outside so much as to set a pattern of turning on F.lux at the same time every day, to settle into a night-time routine.

[deft]

I know the reasoning, I guess I'd just prefer to set it manually based on when I'm actually using my machine. As in, near the end of my usage at night I want it to be very orange no matter what the time is.

[dagurp]

I agree. I live in Iceland and during the summer months it does nothing.

[nebabyte]

Many people aren't attuning it to outdoor light levels.