I have 5 zones on a Sonos system. The whole thing works fantastic!
I don't use online streaming sites through Sonos or anything although there do seem to be a good few you can sign up for if you wish.
In my opinion Sonos is one of the best electronic type products I've ever purchased, very easy to set up and operate and expand to new rooms as required. I did pre-wire many of the rooms when we built although you don't need to especially with the latest speaker system they brought out.
Final tip - I purchased from USA sellers on e-bay at times when the dollar to euro conversion was favourable.