I've used GSM for 30+ years and have always had stellar service. I recently had a new HVAC installed and I'm sorry to say, the service I received this time want as good as my past experiences.
The sales rep that sold me the system neglected to share information with the tech's. I asked to have a gas line run while they were here, they didn't know anything about it, so I now have to pay a premium to have that done. There were a few other items that didn't get done because the sales rep failed to put them on the work order.
I was not given an option on what brand of system to purchase, which I found disconcerting.
They also installed a thermostat that they had been having issues with with other customers, but installed it anyway. So I had to be home to have it replaced.
All in all, this was NOT my A+ experience I've had in the past. I'm sad that my confidence level has gone down considerably after this last experience.