I replaced 2 Honeywell thermostats with these with new HVAC. I didn't see a need for being online, but it sure makes programming a snap. When my cleaning crew comes, they always mess with the controls. The security allows them to change ONLY the temperatures. I have the timing arranged to go back to normal programming before I come home. I would not have gotten online units, but I see no drawbacks.
We are out of town about half the time and are unable to put our thermostat on vacation or away with geofence. Confusing. I keep being prompted to install this device even though it is already installed.
The T6 is easy to program But, what makes extremely difficult is the instructions to connect with the internet. They are so poorly written I had to call technical support to get help. They had to explain what the instruction meant for me to do. I have a computer background so I'm not illiterate in this area. I wouldn't recommend the T6 Pro for this reason.
Quick call to support had the device hooked up and working and no issues at all since. App is easy to use, connectivity is great. Peace of mind knowing we have a professional series vs the big box version with no warranty or support. Awesome!
I like how easy you can set it and control it from your phone once you download the app. NYSEG has savings events that you can choose to be a part of if you leave your thermostat at a set temperature on the hottest days and then you save on your bill.