Our A/C went out on a Thursday, hot. I called at 5:30 pm and spoke with a call center who routed me to a dispatch and said that someone would be out that night. However, it was late and I had to leave for work early the next morning, so I had them come out on Friday at noon. They inspected the old unit and showed me where it was rusting and leaking Freon. The unit was a cheap contractors unit that came with the house and was 11 yrs old, I was the last one on the block to have my A/C go out. The Cornerstone tech put some freon in the unit to get us through the night. My neighbors on both sides of me had Cornerstone AC, plumbing, electrical install their A/C. David and Johnathan, from Cornerstone, came out on Saturday morning, in the rain, and installed the new unit. It is the best money I could have spent. Great unit and for a great price. They were both very professional and did a great job. The weather was cool and humid and it took longer to fill the unit then normal. It was a long day for them, they cleaned up very nicely and made my wife and myself very happy. The unit is much quieter and efficient with a programmable thermostat, which we didn’t have before. Great company.