Hi Trahern!
I've had the chance to listen to the Zep Mini (£299), Sonos S5 (£349, but no ipod dock on this) and original Zeppelin (£390).
The Mini seems well built and not too heavy. The rotating dock is brilliant to switch to CoverFlow and watching shorts videos. The remote is the same as the original Zeppelin and is limited in its functionality. The sound is excellent for such a small unit, but spread/width is limited as expected. I thought it had good bass depth and was pretty good with vocals too. It struggled with volume/output when its turned up (too high!). Pop music would be grand on it.
Its got a 3.5mm input for other sources and USB for syncing with iTunes and/or connecting it to a computer to listen to music through the Mini's speaker.
The Original Zep has better sound, but its bigger, has no rotating dock and its more expensive.
The Sonos sounds the best of the three by far though. Trouble is, its got no dock, so you'll need to buy a separate one (Apple Dock with remote?) and its full functionality is only exploited with an existing Sonos set up...
Hope that helps,
Raihan