"Smart" thermostat question
 

I have a Honeywell CT3500 thermostat that has the "Smart Response"
technology. We have the thermostat set for 78 degrees during the day
and 70 degrees when we go to bed...I'm noticing the air kicking on as
early as 3pm when it's reading 75 degrees (I'm guessing to slowly cool
down the house over a longer period of time?). Is this really an
energy saver or is it mostly for comfort? Would it be beneficial
cost-wise to just turn this "feature" off and use it as a dumb
thermostat?