I agree completely - it's about who's in there and what they find interesting enough to make it into the prose. What is it they feel passionate about?

Either because of this or because of the problem of mechanicalness, I way prefer writing kink porn to anything vanilla. This is partly just because I'm not all that good at expressing lust compared to the best sex writers I've seen in fandom; it's the nature & character of lust that makes explicit sex worth reading, imo.