They do a great job. I have been using their service for a few years for routine maintenance on my home air conditioning and heating unit, and everything runs very well. What I really like about Summit is how flexible they are time-wise. When I worked in the mornings, they would be here before 8 AM to make sure they took care of what I needed them to before I left. I have had the same technician since I started using their service, and he's great. He's always been on time, he's friendly, and he makes sure to clean up after himself once he's done. I definitely recommend Summit!