Minus 1 star only because it took a month to get a tech to come out and set my system up.
I had an existing system. We did not know the code and neither did the previous owners. The tech had no problem resetting the system and adding in the cellular monitoring. Very quick and easy. So far no issues. Expensive up front because you pay for a whole year, but the discount on home insurance almost pays for the monitoring.
Anytime I had to call to set up my monitoring and setup, I was on hold for no longer than a few minutes. Probably best to try and call at off peak times as I did.