I just got ADT because all the equipment was already installed from the previous owners. The alarm sound is deafening. You can hear it from outside. Every single window and door has a sensor. If the alarm goes off, they call me, then the police. I don't have the interior motion sensors active because I have 2 cats. $35/month for 3 years isn't bad. Plus there is landscaping lights on timers, motion sensor lights in backyard and driveway, and lastly I'm in a very residential neighborhood so that all being said, I feel pretty good.