Worth it IMO. Some people know the alarm can give them 3 or 5 minutes and they are brazen enough to stay in the house that long and keep trying to rob you before they have to leave, but the normal burglar would probably get scared enough to just run upon hearing the alarm.
I got robbed last year for 20+k ouch. I HAVE an alarm but didn't arm it when I left the house. Now I do, thanks. lol
There are different types of alarms that you can get for other areas of your house like fire AND burglar. If there's a fire in my house (smoke alarm goes off), the fire department are immediately dispatched.
With the regular burglar alarm part, they call you first to give them the passcode. If you don't know it, they send the cops. That is the 3-5 minutes I was talking about. PLUS the alarm is loud enough to scare someone away.
You can have motion sensors in the living areas of the house and contacts on the doors and windows, AND glass breaks on the windows.
If any part of the system is "opened", then the alarm will sound. Then the keypad(s) which can be mounted anywhere in the house, will show what "zone" is faulted. Such as "Front door", "Back door", "Master bedroom motion", Lving room smoke detector"... etc...
I enjoy the 2 second tone that the front or back door makes when opened during the day when the alram is not armed. I can be anywhere in my house and know if someone came into the front or back door. It's just a little alert that I've grown accustomed to and like. The keypad makes the very low tone and I know a family member or someone has walked in. I could be in the basement or wherever. Without the tone at the keypads, I'd never hear the front door opening. It's cool.
Also, at night when the family is going to bed, you can bypass the interior motion sensors (press 2 buttons) and only have the perimeter doors, windows, glass breaks on. This way if you are walking around inside at night, like going to the kitchen for some water or drugs etc... the motion sensors won't be triggered but the outside (perimeter) is still "alarmed" in case someone tries to break in through a window or door, glass.
Bottom line, if I had my system ON when I left, the guy wouldn't have stayed in my house for half an hour like he did. He went through 3 floors of everything I had. Found all my jewelry, cash, credit cards, electronics, financial papers, everything. With the alarm sounding, either he will not hang around that long or the cops will come because they were dispatched or your neighbors will come because of the loud alarm. Mine actually says "Burglary Burglary, You have violated a protected area. The police were called. LEAVE IMMEDIATELY!" lol Really freaking loud. Then it just does the siren for a while, then back to that phrase.