i'm a little ambivalent about it... sometimes i like it very much, but sometimes i feel a little silly up there lol.
i feel less silly when i rest my upper body rather than being upright.
it can be a good way to find out what sort of movement you like, and where where exactly you like it etc. the guy can learn a lot that way too (can be hard for them to figure out sometimes).
one thing i've never tried (that i would quite like to try) is having sex in water (like in the ocean, i guess). don't know how that would go exactly lol.