It depends on what one means by "garbage", but I've found that hard-wired systems (i.e. wires for all sensors) backed by something like the standard Honeywell A

It depends on what one means by "garbage", but I've found that hard-wired systems (i.e. wires for all sensors) backed by something like the standard Honeywell Ademco Vista series attached to a real cellular uplink works most reliably. We use them at home and at business, and for what a home security system is supposed to do (make noise when an intrusion occurs and send a signal out so that you know about it) its the most reliable setup I've ever used. (Not to mention, provides a ton of options for "hacking" your system to your needs.) Just, whatever you do, do NOT let some crazy internet-connected service, like XFinity Home hook up to it. All of your reliability goes out the window the second they hook up their stupid takeover devices.