Are ecobee or Nest thermostats more reliable?

Opinion is split in the data. High-trust community threads praise ecobee's local HomeKit control and HVAC diagnostics, but an HVAC-contractor post flagged screen lines and weak remote-sensor connections on newer ecobee designs. Nest draws criticism on r/smarthome for a wide temperature swing and a polarizing learning feature, though TechGearLab measured strong real-world accuracy on the 4th-gen Learning model.