MASTERTECH SECURITY SVC INC

have been using Mastertech since 1987 - in 4 homes sequentially.  They are always responsive.  They installed systems in 3 of the 4 homes, and upgraded the system in my last home.  I am waiting for my new home to close so that I can have them come out and install a system in that home as well.  In the old days, they did mostly wired installations, but now wireless make it so much easier and less expensive to have a system installed.  Brian, the technician, is always available, not only to do repairs and upgrades, but to answer technical questions. Once you are their client, they won't increase your monthly monitoring fee.  If you are having work done at your home, they will put it in test mode for however long you need so that you won't get false alarms. I couldn't be happier.  
I told Brian that I never used the "away" mode because of false alarms triggered by the infrareds that came with the house. He upgraded the infrared sensors to eliminate false alarms. The newer infrareds won't be triggered even by most indoor pets. Problem solved.