Just last fall (September 2012) we installed a Water Furnace geothermal heating and cooling system. I was looking at our power bill, and I can report that our electric usage was 1669 in 7/2012 and 2485 in 8/2012, but skipping to this year our usage was 927 in 6/2013 and 865 in 7/2013. (That would be a billing period that ran from 6/3/2013 to 7/1/2013, so it's actually June). Anyway, I'll keep collecting data, but it seems the new system is saving energy.
See that black flexible join in the air duct above the unit? That is for noise control, so vibrations from the fans don't reverberate through the ducting. Now, I'm sure any new furnace/air conditioner was going to be quieter than our old one, but the near silence of this system is amazing to me. It's really hard to tell if it's on, unless you are near a vent and can feel for warm or cold air.
Because the cooling comes from the four 150 foot deep wells, there is no noisy, ugly unit for A/C next to the house anymore! That's a plus.