My experience with this is not good. My sisters all decided that my aging parents needed this for "peace of mind" and ordered the system many years ago.
My folks live in the country on acreage and are 7 miles from a village police force.. otherwise it is the county mounties that attend to any calls.
Since I am on the -- call list -- in the event of emergency, I am a first responder.
Usually it is one of my folks "forgetting to shut the door" leaving the house, or the dog sets it off, or once a love bird got the blame, but each time this happens, it sure brings the hackles out on your neck, and the heart pounding to find out who or what happened to set it off.
Over more than a dozen years, probably 18 more accurately, they have spent a ton to have me be on edge when that phone rings and it is the alarm company on the other end. Though I live 10 miles away, I ALWAYS get there before the cops....since they are dispatched to any roaming authority that might be within an hour of the place. So speedy they are not...remember this when YOU sign on the dotted line.
Sometimes the thing goes off...for no reason....once not long ago, while both were away from home and I knew it had to be the REAL DEAL, only to find that it went off at 4am, maybe for lack of air movement in the house.
Personally I would spend the up front money on a good system that will auto dial YOU no matter where you are so YOU can turn around and call the cops after assessing or sending a neighbor over to view the surroundings. Way cheaper and you can make a far better system with camera motion lights on the house and even sirens and flashing lights that surely would frighten off the boldest thieves who would NOT be happy with the attention the place was throwing his/her way.
Also signage is 90% of the show....led lights that go red on a dummy camera when a car pulls up will do wonders to anyone who is doing a "delivery" to case the place.
When you think of the cost, and upkeep of an online system over the years, it does amount to a pile of money. And it might not do what you want it to do, since a "silent" type alarm may NOT scare off a criminal who is in and out in 7 minutes...short enough time to get away with it.
There are some fine systems out there that will autodial you, run flood lights that flash, and makes enough noise to wake the dead...and I would think that this would make the "wife" feel better, and would not send false alarms to the cop shop, or other heat failure measures to anyone who has to respond....while save a major chuck of change in the long run.
Jist my two cents....tho