I don't have any moral objections to the creation of anatomically correct models.

From a practical point of view, however, I think detachable genitals are the way to go.  If you're doing porn, or erotic art, or whatever, you'll probably want a lot more detail than someone doing artistic nudes or clothed figures, and it's a waste of polys.  Maybe you could even have high and low-res naughty bits.