If you are still choosing between Honeywell and Ajax, there is a clear choice. Of course, Ajax is much better. I mean, it is a progressive brand with modern qualitative devices. I've been using that system for a while. And there are still no complaints about it. I recommend it to everyone who is considering a new professional system. Moreover, this system will stay actual for many years. You will be able to connect more devices as well. And yes, you are right. It works with a sim card and does not require a wi-fi connection.