Thirty some years ago, I got into the Alarm Business for a short time so I will give you some old advise and opinion that might not be totally accurate today.
Is this going to be something that you are going to be installing or having done?
I presently have Sonitrol, a listen in device that has microphones strategically placed around the building and when the alarm is set, if there is any disturbance such as banging on the door, it will activate the alarm. The operators will listen for sounds that they have been trained to know as a break in. Very secure and it also has a hold up feature. Once activated, they can hear and record everything that is said. This system is at my business...
I had a hard wired system in my home and it was made by Ademco and was a trouble free system. At that time, wireless was just coming to the industry. It has improved a lot since. The one thing that I have always felt...... Ademco is one of the leaders in the security industry. You cannot purchase it as an individual, however my suggestion to you would be to check with some installers for prices and suggestions. Also, find out where the monitoring is going to be. Some companies have systems monitored many states away. I would prefer to see a local monitoring station, but they are becoming less popular. It is important to know that you own the equipment and that you don't get yourself into a monitoring contract that locks you in for a long time. Many install companies will try to give you a install price and they will own the equipment and you pay a monthly fee for a contract period of 3 - 5 years. If you don't renew, they remove the equipment and you have to start over again. Make sure you read the contracts carefully and know what you are signing before you get into a system. There are a lot of good companies and installers out there, but there are also a lot of questionable characters that will promise the world and deliver junk.. I know that all too well, because after getting out of the business, I needed another system for one location. I contacted someone that I knew and had them install a system. I just assumed that he wouldn't put in junk, but I was mistaken and was stuck with a monitoring contract for 3 years that I couldn't get out of. A lot had changed in a short time and I wasn't up on all the changes. The problem was that the monitoring station was in another state and that I was paying the long distance charges for the calls and there were a lot of false alarms because of poor equipment.