Would love to give them 5 stars because the result was fantastic, but getting there was a chore so I can't give them a perfect score. They care about the work they did and my new system performs really well (my house gets cold and does it fast). I worked with John and Kevin (I think they are co-owners) and was thrilled with the deal and warranty they worked out.
When I say the install was a chore, I mean that they were constantly late, the install went days over schedule and there seemed to be drama at every turn. In retrospect I believe the drama and extra days in the cycle were a result of them making sure things were done right and appreciate that they kept showing up until the job was complete -- not just slapping things together and moving on to the next job.
I feel like a got a better product, a better install and a better price with Diamondback, but had to overlook a couple of things on the customer experience front in order to get there.