I scheduled an air duct and dryer vent cleaning with Advanced after my brother had used them with extremely positive results. The field rep who showed up, Billy, was extremely courteous and actually came much earlier than the one hour service window I was provided. He was done in less than two hours and the outcome was tremendous. It's a pretty cool profess how they do it. Billy made an entry point into our ductwork and inserted an industrial vacuum hose that extends from the truck. While that sucks everything out, he went around to each individual vent and vacuumed and sanitized each vent duct and its cover. He also showed me the before and after for each vent, and the results were incredible. Once you see just how nasty these vents can get it left unattended for long periods of time, you won't think twice about hiring advance. No surprises on the bill as it was exactly what i was quoted on the phone. The sanitizer is a great touch...house smells great and air feels lighter. Will definitely use them again and recommend to everyone I know.