Well, I think there are some great thoughts on this. It comes down to reader and mood in the end. I read a variety of stories ranging from the pride and prejudice type romantic suspense to full on erotica. Bring it on. If I look at my bookshelf it's hard to categorize myself as a single type of reader.
I love a bit of steamy-ness, but I do agree it has to fit the story.
Also--this is something I wonder for my own writing--how do you find the balance between sexy and honesty? I mean to totally ignore our sexual side seems false sometimes (and has known to irritate me when reading a book).
Hmmmm also, yeah I write sex scenes (actually the story I'm writing now is the only one with it--see I can write stories without it too, haha) but for me it's about learning to open up, you know, loosen on the page. I've been told before that my writing isn't brave enough that I shy away from getting into the nitty-gritty. (Obviously it's something to do with balance. Blah, I'm rambling. *Is still figuring it out)
Summary: If there is conflict and tension and the story can handle it. Yup. I'm happy with details.