If you like to keep your iPhone or iPod in a protective case, you will be happy to note that if you pull the little insert out of the dock that will give you more room to slip your iPhone or iPod into the dock without having to take off the case (the dock should accommodate most but not all iPhone cases). It's also worth mentioning that you can opt to have your music automatically start playing in a certain zone (room) as soon as you dock the device. You can also opt to have the last song you were listening to automatically start playing.
In the end we came away feeling the dock was simple to set up and thought the accessory was a good complement to a Sonos system. While most people will use it for their own music, the product's other bonus feature is it allows you to drop a friend's iPod or iPhone into the dock and instantly stream his or her music. In other words, the Wireless Dock is an equal-opportunity dock: it doesn't discriminate between your device and someone else's. It also offers an all-digital connection, which is what you're getting when you stream directly from your computer or a networked drive.
The biggest drawback of the Sonos WD100 is that you lose the convenience of using the iPhone or iPod Touch as a wireless remote for the system while it's docked. Of course, a lot of households have an older iPod or two sitting unused in a drawer somewhere--and the Sonos WD100 is a great way to put them to work. The WD100 works with all iPhone and iPod Touch models to date, the iPod Classic, and the iPod Nano from the third generation onward. You can just load it up with music, dock it, and forget it.
The other major downside of the Sonos WD100 is the price. At $119, the Wireless Dock is a little expensive. At this price, we would've liked a line-out jack that would have allowed the WD100 to double as a full-on ZonePlayer, allowing connections to a stereo or powered speakers. But for dedicated Sonos fans who don't feel like buying a more expensive and convoluted networked drive--or those who want the flexibility of streaming music from multiple iPods or iPhones--the WD100 is worth strongly considering.