Is it worth it?
Depends on what you need it for. Do you want to reduce your heating costs? Then it can help. Do you want to make your home smarter? Then it definitely helps.
In my case, I got it because I always forget to turn the heating down (I've only got radiators, so no central stat, nor a timer) and I don't have a super regular schedule, so simple TRV's with programs didn't do much for me either.
And I like the integration with IFTTT, so when FC Bayern is playing, the lights in my living room turn red and the thermostat is set to 20°. Now I just need a smart fridge that makes sure I have beers in there for game day.