Programmable Thermostats??

JTW

OK, so I am not a plumber, but a friend of mine had an interesting point and Iwanted to get some input from the people who actually know. So I was stating that i have programmables and they save on energy by cycling when I do and do not need heat. He says that the recovery from the cycling of the thermostat will eat up any energy savings! His point was the amount of energy used to sustain vs. the amount of energy required to recoup back to say 70 degrees from 65 degrees. What are the realities? Leave them flat most of the time or program them?