There's more than one story I've come across where I've thought, ok, this is interesting - if ONLY the author would stop the action every half chapter for another sex scene, we might actually get to the end sometime this year. PWP is one thing but a story with a genuine plot that's also stuffed with porn is another.

Sex scenes are like romantic reunion scenes IMO, or anything that brings the story to a crashing halt - if the author is putting them in for their own pleasure, well great; but if you mean for other people to read it I want to tell the author "please save that version for yourself."

But a lot of people like to read that stuff so oh well.