FWIW I'm in the process of installing a heat pump; it's arrived, still looking for a contractor to do the install. Part of that involved upgrading our thermostat to eek out the most performance. Lot's of hype in that market! Nest, Ecobee, blah, blah, blah. Wasted a lot of time sorting all that out.

Ended up going with a Honeywell Prestige IAQ system with Redlink and internet. What might interest you is it only requires 2 wires for the thermostat, all the rest is in a box by the HVAC. Plus all the reviews are pretty much stellar.