We've been using Allied Services since 1995 when we originally built our home. I've had them on a service contract so they come out twice a year. We've had some difficulty with air conditioner parts but they were always here to take care of it. They gave us a good price when we had to buy a new unit. What I like is that they know my complete system. I have a humidifier and electronic air filter system. I've been treated very fairly, they respond to every one of my concerns, the techs are competent and knowledgeable, and I've been very happy with them.