It's a dynamic way to heat your house, you decide what's heated, if your in the house you just overide the settings to what you want or allow it to decide.
The simplest way to save money is to 2 zone your house, upstairs and downstairs. How often do you use your bedroom once you've got up in the morning?
Also, you set a min temp for all the rooms, an OFF room in my house is 17 degC, an ON room is 21 degC.
You should never let your house go fully cold in the winter, the start up to warm uses masses of energy.
I save £450 a year using this system, 8 zones.