To add my $0.02... I buy and sell numerous bikes every year. When selling I advertise on both CL and BARF. So far I've had better results selling through CL. I assume this is simply because it hits a much wider audience.
As others have mentioned, you have to sort through some BS when using CL. But that doesn't mean BARF is immune to flakes either. I'm especially annoyed by the folks posting motos wanted on BARF, then when you reply with something that fits the description of what they are looking for... and they don't respond, or ever post that their search has concluded. Very annoying