Though I must say, depending on the type of stp model you might notice more or less smellyness down there.
With the types that cup your anatomy (Peecock, Emisil, Freetom etc) it covers your anatomy and thus, blocks smell. But with the EZP type, you wear it more to the front and not covering your downstairs bits unless when you're peeing. This makes it more comfortable to wear but I do notice my crotch smelling quicker/more often than with the other stp type.
But no, this isn't a pee smell and I'm pretty sure that when I've had a colpectomy most of the smell will go away.