said by AKA06:Would you mind elaborating on your specific issues with mounting, fan programming and the heat anticipator algorithm?
For example I have the CT80 which mounts with four tiny screws in the corners. I have 4x4 boxes with single-gang mud rings. So my CT80 screws are screwed into the drywall around the box. Nice, huh?
On the other hand, the Honeywells have keyhole slots to mount directly on a mud ring. They also sell an OEM plate with multiple mounting holes. This let me change the stat orientation without opening the wall to turn the mud ring.
Fan programming ... My Honeywell 7-day stats let me program the fan to switch to ON or AUTO without turning on the heat or A/C. So for example I program the fan to start at 5 PM even if there's no call for heat or cooling. And the fan shuts off at 8 AM. Weekdays only, of course.
Heat anticipator ... the Honeywells let me set CPH based on heat type. It's not perfect but it did a better job of not overshooting the set point than the Radio Thermostat. I've seen no evidence that the CT80 even considers this an issue.
Also I didn't use it but the Honeywells have AIR (Adaptive Intelligent Recovery) so you can have the house at the set point AT 5 PM, rather than simply start calling for heat at 5 PM. Good idea but on the coldest winter mornings I got tired of the furnace starting at 4:30 AM since my setback temp is 60 F.
I've seen these Nest things and so on. I don't want a learning stat, I want one where I can tweak their assumptions ad nauseam via a web interface. There are better web-accessible stats out there but nobody at this price.