I think a lot of it has to do with your area and you also have to be a skeptic or you will just end up angry or disappointed. I seem to have had good luck overall with CL, but my local bike section is VERY slow, but what little gets posted is generally a pretty good deal compared to what people on here are paying in other areas.
The pickings are slim, but if you're patient there seems to be some killer deals and not a whole lot of competition. I've called on things that have been up for weeks at a very reasonable price and they've still been available.
The farthest I have driven for a bike is an hour and I don't think I would drive any farther than that because of stories like you guys are telling. Being out an hour of driving is frustrating but not enough to send me into a rampage. If I were to drive 2 plus hours to get a bike and then get screwed, somebody is probably going to get hurt.