When we moved into our house 3 years ago, the previous owner had a magnet for them on the furnace, so I decided to give them a whirl. We have not regretted it. We have them come once in the spring for AC checkup and once in the fall for Furnace. Our last visit was this past Saturday. Greg is the serviceman that has come each time for the past 3 years. Super nice guy and he is VERY thorough, taking all the components out and cleaning them and doing a thorough inspection. Never replacing things until they actually need them.
The best part for us, is that they have Saturday hours... however, there are not set dates. You just call and get put on the Saturday list. On the Saturday they are doing work, they will give you a buzz and see if you are home, if so, they will be there very quickly and if you aren't available, they will call on the next Saturday they are out.
I had mentioned that we would be looking into a new AC unit in the near future and even though he wasn't there for that, he took down all of the info and is going to drop us off a quote.
There prices are very reasonable and the service is GREAT!