I got this since I have a three floor house and the temperature between them varies considerably. By supporting remote sensors it can give an average temperature between chosen floors for each set point (just remember to change the batteries every year...).
Unfortunately there is no way to get it to circulate air when the temperature differential reaches a certain point; the only circulate option is a fixed percentage of time on whether or not it's needed. Additionally, the thermostat itself has no battery backup for the internal clock. If you want the clock to auto-reset, not only does it have to be on WiFi (it picked up my router's time server) but without the app you cannot control the timezone (mine was stuck to UTC until I added the app).
Additionally, there's no real integration with other smarthome items. If you're looking for more flexibility and no reliance on an app that may be discontinued at any point, I recommend the Z-wave one, but you'll pay more for a hub and sensors. The app is kind of handy in a house like mine, but it's slow to load.
My only complaint is there is no vacation schedule you can set. Or at least I cannot find it. Otherwise a great product that links to our Lyric security system