Well I worked for the same company that Mike did for ~2 years and worked for brinks for 5 years prior to that.
I am totally out of the industry now, so I do not mind posting my thoughts.
1) Your installer and his work quality will do more for your long term happiness and satisfaction than any other single factor in my humble opinion.
2) I would not have a system monitored by ADT, if it was free. They have too many multiple monitoring locations and sell monitoring accounts, as a result you have no idea who/where is actually monitoring your system, and I know numerous horror stories....
3) Brinks/Broadview is a notoriously slow adapter. As a result they will never be bleeding edge technology, and they will often be more restrictive no "pet friendly" PIRs until 18 months ago) but their false alarm rate is literally 1/20th of any other large company.
4) If I personally felt the need to install a monitored system, I'd PM/call Mike B ^^^ great guy, knows his stuff and local support.