We've tried to like Craigslist. We really, really have. But, for us, it just never worked out. The problem with having no barrier to entry (read: paywall) is that it attracts a lot of lookieloos. I'm sure there are some wonderful couples on there, but weeding through all the fakes takes way more time than we're willing to invest these days.
I should add that the last straw for us was when our posts started getting flagged and removed because we refused to respond to every (john) thomas, dick, and hairy (dick) who sent a "hey let's fuck".