I really can't complain about Orange County, CA's board. Yes, it's 90% Xmart and beach cruisers, but overall I give it 4/5. I've kept my eyes open and it's paid off a couple of times. As with anything on CL, if you want a bargain you'd better know how to read between the lines, have your research done, and have your cash in hand.
Los Angeles is a different story- holy cow, there are a lot of fabulous bikes that pass through there. I wish it wasn't so sprawled out, it makes getting them almost impossible. By the time I drive up from OC they're usually gone, and your negotiating juice is pretty much impotent if you've just driven 1.5 hours to SEE a bike.