We've been using them for a long time and have a maintenance contract with them!
The service we got from Choate's Air Conditioning, Heating, & Plumbing was just fine. The service man came in the center of the allotted time frame, and he called ahead when he was close. Kevin was his name, and he was very courteous. He asked about the mask and put on booties. He showed me a couple of things where the overflow in the pan was thirty-something years old and needed to be replaced. So he replaced it. He explained everything, went over everything, put the date on the filter and that was it.