If they're anything like the Twi'leks from Star Wars, then I bet their porn is just as good as ours. Unless if they're being forced to film themselves satisfying their Hutt masters on Tatooine. That would be the equivalent of Lisa Ann having sex with a giant slug. However, if they're like a microscopic fungi or bacteria, or even some form of distant plant life, I would presume that their porn would all look pretty much the same, and not very erotic.