LOVE IT....got it for xmas and will be doing an expanded Sonos system in my new custom home instead of a in-wall!

I had one and loved it. That was about 3 years ago. Then I sold it because I didn't need multizone audio.
I'd say that it is great at what it was designed for which multizone audio. However, since I believe that they've got out of the business of making controllers and require you either use an Apple or Android device, you could probably achieve much the same result using an Apple device (e.g. an iPod Touch) and an Airplay compatible speaker or AppleTV connected to speakers.
The Sonos solution is very plug and play and very each to use, but I think that the AirPlay option is equally viable depending on your situation.

So despite what I wrote above, I just picked up a Sonos Play 5 package from Costco for $450 (it includes the Bridge that is required to connect the Sonos system to your network, and a 12-month Rhapsody subscription that I probably won't use).
I spent some time looking at AirPlay options and felt that the Bowers and Wilkins A series of speakers were the most comparable. The A7 is comparable to the Play 5 and the A5 is comparable to the Play 3. However, the A7 is $800 compared to the Play 5's $400 cost and the A5 is $500 compared to the Play 3's $300 cost.
As with Sonos, both need a device to make them work (in this case because they're AirPlay, iOS only). Furthermore, AirPlay works over WiFi along with all of your other networking stuff. It can stutter and be laggy depending on what else is going on. The Sonos on the other hand uses its own mesh network. Finally, I use Spotify to listen to music. With the AirPlay option, I would be using the iOS device to stream Spotify to the speaker. With the Sonos, my iOS device is just controlling the Sonos unit, which is streaming Spotify.
So 8 years on, Sonos is still the hands down winner!

Sonos is awesome. Along with Nest (the new thermostat), they define how the new smart home/internet of things is going to be designed. And no other manufacturer comes close in terms of ease of installation and use.

The units are dead-easy to install, especially if you have in-wall speakers that wire to a hidden room/closet.

The ipod/iphone controller is intuitive for a child or even a wife ;)

You can have each play individual stations or easily group them for totally synchronized whole-house audio.

The only ding is that the units are $450 per room, but if you can do that, do Sonos.

I agree, Sonos has become the standard for myself although they are pricey! Their new soundbar is amazing...but at $700 it's a pricey option.

As to Nest, agreed...it's a PHENOMENAL piece of equipment. Have had mine for almost a year and have seen energy savings and is very good at getting the house where I want it without me telling it!! Well worth the investment...not to mention the greek cred!! :)

This is a semi old thread but my understanding is that Sonos uses and iOS device or Android device as a controller but the streaming etc still comes direct from say Pandora to your Sonos Amp and then to your speaker. With airplay or bluetooth etc you are streaming (not just controlling) from your iOS or Android device which will have significant impact on battery life.