I purchased a tado when it was very first released in the UK. It was easy to install myself and the tado support team were on hand to provide lots of useful help and support. Overall it did a great job of keeping our apartment warm while also saving us money. I also really liked the minimalist clean design and the fact that it just got on with it's work in the background. The biggest plus is the reassurance tado provides that you're only paying to heat your apartment when you're actually home.
There were some teething issues with the first generation. The first generation communicated on a similar bandwidth to new 4G masts installed in our neighbourhood and this meant that our tado would often become disconnected and need resetting. I think they've fixed this with newer versions though, and to be fair the CEO reached out to me and offered me a replacement 2nd gen tado - this is fantastic customer service!