Do you use a crotch strap as well? Does it bother you?
I have one on my BP&W and I have to say no it doesn't bother me in the slightest.
The lack of one on the jacket type that I did my OW course in did bother me though (I carrying a bit too much round the middle so if the waist strap moves up off the widest bit it is moving all the way up on a standard BCD).