I was reading on the Goodman web site that their 95 percent efficient furnaces are two-stage, which is a feature that I seek, but that they are accompanied with a one-stage thermostat. I thought that this seemed odd, given that many other brands mandate that you use a two-stage stat which using their two-stage furnace. Can anyone tell me why the Goodman product requires only a one-stage stat? Is it something to do with internal timing and not really the stat reading the raise/fallin temperature? Thanks a lot.