I have a US model 2720. You can get a European base-map (non navigable) from
here.
The preinstalled US mapping cannot be removed unless you have an upgrade disk for that mapping and are willing to pull the plug part way through an update. Apparently this works but as I haven't spent the cash on the update disk for mapping that I'll probably never use I haven't tried this. As it stands the US mapping takes just under half of the memory leaving enough to load a fair sized chunk of Europe. I have UK, Ireland, France, Spain, Italy, Switzerland, Brussels and most of Germany on mine and should I need otherwise I can just load it from my PC as required. Basically there's enough room to load mapping for all but an extremely ambitious tour (I'd be so lucky).
The allocation of the memory within the 2720 works like this, the Preinstalled mapping occupies a large section of the available memory and can only be changed/updated using some Garmin voodoo that gets invoked by the update DVD. Beyond this there is supplemental memory that can be used for whatever you like; mapping for other regions, TOPO and bluechart mapping, speed camera and POI data etc. Any mapping you load into this area needs to overwrite what's already there. i.e. if you have UK, France and Spain but want UK, France and Germany then you need to upload UK, France and Germany using Mapsource 'Send to Device'. Just uploading Germany would only give you mapping for that country on the GPS and remove UK, France and Spain.
Everything works exactly as expected on my 2720, I'm very happy with it seeing as i only paid £157 for it early last year.
