A month or two ago I was hot and heavy to get into being able to play hi res files from HD Tracks and such, so I got a squeezebox touch. Since having gotten the squeezebox, I've used it a LOT, just getting to know it.
These are some of my observations. In my system, it sounds no better or worse than my Sonos, when playing "standard" definition files. I've also found that there isn't a whole lot of hi res music that I'm interested in. So far, I have about a dozen albums in hi res format, but really have to wonder if it was all worth the expense of the hi res downloads.
The squeezebox is quirky. Sometimes is doesn't want to work and needs a reset. Sometimes it won't read my library and I'm running mine hard wired to my router and have my music on an NAS. The available software is also quirky. The Logitech software plain sucks and iPeng is rough around the edges.
Quite frankly, in terms of usability, the Sonos system is head and shoulders about the squeezebox. The Sonos always works and the software is refined.
Of course the downside to the Sonos is that it doesn't do hi res and you can't control it with an IR or RF remote (which is a biggie for me).
When I'm having a party or something and pass the ipad around so that guests can add to the play list and control the music, I use the Sonos. It's just plain fool proof. When I'm kicking back and just listening to music, I use the Touch because I can control it with my Harmony 900 via RF.
In the end I just kept both. The Sonos is reliable and the Touch was so cheap that keeping it isn't a big deal.