I have been using ATT Digital life for the past 2 years. I liked it best because it offers basic call center monitoring and remote management (Wifi & GSM) at a lower price than most competitors (eg ADT) and gives me $'s off my home insurance.
Finally I integrated it with Smartthings last weekend using a PI3 as a server (see below). I am still testing but it looks very promising… You can see the status of all open/close sensors in Smartthings and can set the alarm to home/stay/away. There is also integration with SHM that is very useful (just in case SHM ever works again reliably)