i prefer the higher gears because i feel like i'm getting more power to each turn of the cranks, but in a certain middle ground, it gives me room to move up, increases my cadence, and uses the motion of my legs efficiently without asking too much from them, as constantly mashing the pedals would...
i know i'm sort of a n00b, but that's something i've noticed. it's probably different for each person, but finding a middle ground where you put forth enough but not too much, efficiently use what you put forth, and can move either direction if need be is probably pretty much the ideal, right?