The Logitech is indeed better for travelling - comes with a carry case, and its rechargeable battery means you can take it just about anywhere. Also, if you do pack the mains plug, the MM50 will charge your iPod as well, so no need to pack a separate iPod charger.
The Cyrus would pip it for sound quality, though - but is more of a desktop solution, as it's mains-only. All depends on how flexible/portable you want your Pod dock to be!
Re the Intempo - assuming you mean
this, we haven't tested it yet. Should be getting one very shortly, however.... Really wouldn't like to second-guess how it'll sound, as Intempo docks have been very variable in quality.