Do any games benefit from disabling fog?

[neobrain]

Disabling fog only disables a very small number of pixel shader instructions. It doesn't actually skip rendering of "far" objects, if that's what you expected. The only point in keeping that option is because, as RachelB pointed out, it increases visual quality in some cases. That's also the reason why it's in the "Enhancements" tab, rather than the "Hacks" one.