Short answer: It depends.
Long answer: I don't like bland, generic anime anything, let alone hentai. There're far too many "loser guy hooks up with girl who is inexplicably in love with him" stories out there for me to shake a stick at. Ho hum. If there isn't real chemistry between the characters in a romance, why even bother with the pretext of a story? In the same vein, I'd rather pass up guro-style rape hentai and the like. I can't relate "repulsive" and "arousing" -- I just can't.