I have an Ecobee. Agree with you that the killer feature definitely isn't the self learning stuff.

It's simply:

- Has WiFi (update from phone)

Then also:

- Being able to link with Alexa or similar to do things like turning off when you leave automatically

- Custom programming modes. So instead of setting a temperature at a single time during the day (home/away), you could do (morning/home/home2/afternoon/night/away)

- Can run my fan once an hour automatically for just 5 minutes

- Looks cool