I don't like the monitoring services and believe they are a rip...used to work for one years ago.
Stand alone systems are best, with a LOUD outside siren and flashing strobe lights. Camera systems allow you to monitor while you are out of town either on your laptop or smart phone.
Not to mention, most city or county laws give you 1-2 freebie false alarms then start charging you a fee~!~
Just my opinion...