I had a very positive experience with Price Busters Plumbing who were able to quickly and successful fix a tricky condo plumbing problem. 
I had a situation where there was a bad smell coming from the bathroom of my condo, and after a visit from a different plumber who could not figure it out + baffled building maintenance, did not know what to do. I sent a request to multiple plumbers on Yelp describing the situation and received a message back from Price Busters detailing what they could do for odor detection, as well as a very reasonable price quote for the investigation. The plumber arrived on time, was nice, and went to the extra effort to diagnose the problem including checking with neighbors for leaks (unlike the previous plumber I had used). I got an immediate quote for the fix (also reasonable), and was able to get the fix then immediately by installing a wax seal (job took ~2 hours). It has been a week, and the smells are gone! Would definitely recommend/use Price Busters again.