I think this really depends on what you're looking for.... I love finding new girls, even potential gems.
Finding ads and investigating whether they are fake or not is something I highly enjoy.
But there are risks to that high reward and that's where skill, common sense, street smart, experience comes in....and of course review boards.
I for one know of a considerable amount of girls that only advertise on BP, don't need to advertise boards and are 100% legit... so to each their own I guess.
Regarding the troll accounts? Any medium built to attract a paying customer for a product or service will have a proportionally increasing amount of trolls on it ; both the people posting (scammers, pimps, BS agencies, etc) and even the site operators themselves (increasing the # of articles just to increase their google ranking for example).
And it only makes sense that sites that charge for visibility will have a lower number of scammers paying for that visibility (ex: merb sponsored ads). In exchange we see an increase in shill accounts to balance that out lol