I have one already, believe me it is very interesting and a good time pass. The best part is, at nights we can ask the Google to play songs and ask Google to stop after specific time. Obviously I will be in deep sleep by then.
For kids above 13 years, its a good informative device, they can talk to them to learn new things and also the communication and listening increases.
It pairs with my chromecast and my android mobiles. It will work as bluetooth speaker for Android alone.
A best buy, kids will get addicted but their eyes will be saved. Go for it, instead of getting them screens.