My roommate bought a Nest about 6 months ago and I haven't seen any real potential or usefulness out of it. It doesn't actually add functionality to my HVAC sys

My roommate bought a Nest about 6 months ago and I haven't seen any real potential or usefulness out of it. It doesn't actually add functionality to my HVAC system, just more ways to complete what simple function my old thermostat could do -- with more points of failure.