Just. Good. People.
It's really very simple! This team shows up on time, sends very knowledgeable tech/installers, is straight forward with details (good or bad), listens to and answers all of my questions, is helpful in my understanding of the repair/replacement options, doesn't try to sway me one way or the other except where asked, is fair with pricing (compared to quotes from service providers), cleans up afterwards, follows up on things, makes sure you're happy before taking payment.