The real cost savings of this system is in the thermostat schedule, however, at this moment there is no option to take advantage of it.
What I mean is this, in my opionion there should be 2 thermostat schedules for each thermostat.
One for when the system is in Armed away mode (So when nobody is home).
And a schedule for all the other modes (Armed night, armed stay, and unarmed).
This way you can schedule your thermostats for when you're home, and know that when you're gone you are saving money on your thermostat.
I have done this in the past with setting rules, but the real solution is being able to setup 2 schedules. Right now it's set to be 78 when we're away and 75 when we're home. However summer is hitting and humidity is here in the afternoon so we like to keep it one degree cooler in the afternoon. With a schedule this would be no problem, but when using rules it gets a little more tricky to get this done and run correctly.