I had experience with 2 companies. I sure wish I could remember their names. BUT, here's the deal. Once had a fire, pressed the "FIRE" button, alarms went off. No fire dept. came. I used a neighbor's cell phone and called the fire dept. When we asked the security company later why they didn't send the fire dept they said they'd TRIED to call us. Well, apparently they call to double check. NOPE -- can't do that if the fire burns the phone lines!!! They chewed me out for calling the fire dept!!! Had I waited my whole house would have burned down.
My other experience is with the company that has a "microphone" (for lack of a better thing to call it). If the alarm went off they'd call out over the mike asking if I needed help -- yes - that's the one I liked. No phone call back to me.
My folks had a system that beeped every time the door was open. Well, we noticed after a while that not only was that irritating, but after a length of time we got to where we ignored it totally!!!! That's no help! It beeped every time - whether the system was "activated or not".
good luck!