Thanks, guys, for the great help on my previous thread.
My HVAC guy got back to me, he said he was planning on using a Honeywell HTH8320U1008 to control the dual-fuel setup of my old Rheem 13 SEER and new Prestige 90 Series LPG furnace. While it looks like a nice thermostat, what little I got could google on it said nothing about "contour comfort" or modulating furnaces.
He said he would check out the Rheem model RHC-TST401MDMS I suggested. There's still time to switch gears on this. I'm leaning towards the Rheem, if only because I hate my current Honeywell thermostat so much. You probably know the type- the instructions say, when finished programming, hit "run program". On the other hand, if you're programming and need to cancel out, hit "run program." How it know?
Anyway, given the HP/LPG setup I'm getting, will the Honeywell give me as much economy and ease of control as the Rheem?