I can't think of any off hand.. BUT it would make an interesting experiment. One would think you would get better hop extraction from wort than with just water.... But I don't know.
EDIT I just did some googling and this thread popped up.. I haven't read the whole thing, but in the third paragraph of the first post, the OP talks about his theory that aromatics would transfer better in water than wort... There might be more in the whole tread... but it is an interesting thing you brought up.
I've never thought about it either way. I've just used water.