Uh!, better check. I think these might be the ones they can turn on and off when they want to. Like your hot water heater with load management. If they are plain old energy saver type where you can program day/night/weekend settings then by all means get it.
SMECO CoolSentry Programmable Thermostat and Installation
I have it, itcan be programmed several different ways and there has only been one instance where the ac was "held" for a brief period of time. I didn't even notice a difference in the house. I say it is well worth it.