I've used it once, and it was actually quite a good time. I posted an ad, and got a response. She was fairly attractive, looked exactly like her pic (apart from a different hairstyle, but hey..), and after meeting by a restaurant down the street, she came over & spent the night.
I've posted a few other times and not gotten anything, even when using the same text (or close to it) that I had that one time. I did get a few nibbles, but let them go without a response because I didn't like what I saw or read.
I knew a guy at work who would post ads (internet personals, before Craigslist existed) and agree to meet in a public place. He'd actually wait across the street or down the block so that he could get a good look without her knowing; and if he didn't like what he saw, he just turned & left. Mean, I know, but it also avoided episodes like JasonDawg's.