Bought my Zumo 550 deluxe less than 3 months ago, specifically to use on my Norway trip. I didn't bother with the 'full' model as I am not het-up about having all the maps on the device hard disk - I can download extra maps to the SD card from the DVD-Rom enclosed anyway.
Got a very very good deal from one of the electrical stores on Tottenham Court Road - it was much cheaper than anywhere else. The maps are brilliant - it works with my phone and I can download podcasts and music onto my SD cards and listen whilst I ride. STRONGLY suggest buying the Star1.com Zumo headset kit though.
Compared to TomTom 6, the maps are just as good and the Zumo has tons more useful stuff on it, like a decent compass, altimeter etc. Download extra POI's from poihandler.com. I now use it all the time, even to and from work, as I can answer calls and listen to Russell Brand. How cool is that!