Sorry to hijack the thread to discuss a 'rival' device but I thought it'd be worth posting this in here rather than creating a new thread.
After my deliberations about purchasing one, I got a Google Home imported to the UK and have it set up and in use.
First things first, although it says its currently unavailable outside of the US, it works fine within the UK.
I have it integrated with my Philips Hue system, Nest thermostat, Chromecast-enabled speakers (Spotify Premium account) and Chromecast-enabled TV.
With respect to all these services, the Home performs admirably.
Hue: All commands work fine. "Switch the lights on in living room", "Dim the lights by 50%", "Set the living room to purple" etc. etc. I can't set a timer though such as "Turn all the lights off in one hour"
Thermostat: "What temperature is it in here at the moment?" and "Set the temperature to 20 degrees" work fine. I'd like to have the ability to adjust my schedule (e.g. "Set the temperature to 10 degrees at 2PM" but that feature isn't available yet.
Music: Probably the feature I use most. "Play MTV Plugged by Nirvana" on the living room speaker", "Play Chromatics Kill for Love on the downstairs group" - all works fine.
TV: I basically use this for Youtube clips and movie trailers. The Chromecast can use HDMI-CEC to switch the TV on and switch it to the correct HDSMI input which is pretty cool.
I use it a lot for basic Google questions "How many millilitres in a cup", "How old was Leonadro diCaprio in 'Catch Me If You Can'", "What time is it in Kuala Lumpur right now" and so on. I've also used it to call an Uber which is pretty cool.
With respect to limitations, you can't set reminders, calendar events, use it to find your phone, text your contacts, send emails, play password-protected podcasts... the list goes on. It is quite limited at the moment with respect to what it could be
I bought it for the basic home automation functions listed above, I'm assuming Google will release a slew of features over the coming months. Rumour has it that they're working on some sort of voice authentication process so that you and only you can set calendar entries etc.
At the moment, I'm happy with it and I know it'll only get better. It can even 'hear' me when I'm upstairs.