Agreed, no power is wasted but it's a lot more expensive to heat with electricity so I use gas.All of this is moot point in the winter though as any power used by the tank goes to heat the house, so no power is wasted.
Good point about insulation. Covering the tank to cut down on evaporation also helps reduce need to heat and the need to deal with humidity. I had my system covered so that little evaporation occurred but opened the fuge to allow some evaporation because I have low Ph and wanted to add more kalkwasser.