We've used the Door Doctor for years. Happened across them, and the service has always been top notch. On one previous occasion, the work hadn't quite been done properly. When we had them back, the installer asked some questions, found out they had been there before, and didn't charge for the service. Only for the part. This was the one time (out of about 6 or 7 different requirements in different homes) things were not 100% and they made good. The most recent call involved a seemingly dead opener that magically started working again when the service arrived. What we got was a reasonable explanation (it's old equipment), descriptions of a variety of alternatives to be done should it happen again, and we were incredibly pleased. Talented, conscientious, and reasonably priced service. And he arrived on time.
Oh, and I was able to book an appointment within 24 hours of my call (we weren't an emergency).