I have used GH for over a decade, first at my parent's house and now at my own little house. The alarm at my parent's house was installed (brand new) by GH. The system worked great for over 15 years. The alarm at my own house was installed by builter, so GH only activated it and monitored it. They activated it at a nominal charge (I guess it was for the service of activation). GH charges me the monitoring services at $18/month. It has been 4 years now, and they have not raised the price. When I have false alarm, the monitoring company call within 3 minutes.
GH is owner operated, so the guy is free to negotiate. He is also quite knowledgable about all the technical aspect of the alarm system. I feel that my security system is in good hand with him.