They have a 3.9% ("green") tier without a high-risk fee, but I don't think the adult companies qualify that one.
I could be wrong, but I didn't find a clear breakdown of who qualifies for each plan on their website. I'm guessing the 3.9% plan and their non-profit plan are there so they can present as a normal payment processor.
CCBill's fees I think are like 11-15% plus $1k per year, pretty insane but underscores the risk