- Runs off AA batteries, for easy replacement of batteries. (Carrying spare batteries and replacing them on the road is much cheaper and easier than carrying a spare charger, for instance)
- Anchor drag alarm, which works surprisingly well.
- mini-SD card slot, allowing 2GB of map downloads.
- Handleba Mount, for easy use on a bike
I loaded up the unit with Bluecharts v9.5 North Americas for the Virgin Islands and discovered what a rip-off that was. You literally pay $100+ for each tiny chart available to you. It was amazingly costly. The North America City Navigator package was much better ($120 for all of North America). As an aside, you do not want to buy map packages from Amazon.com, as they usually have out-of-date versions of the maps (links provided in this entry reflect where I bought mine). Maps are locked to the specific GPS unit, so you can't share maps unless you buy the maps pre-loaded into a mini-SD card. The downside of doing that is that you don't get to put together way points, etc. on your computer and then download routes to your GPS unit.
All in all, I'm pleased with this unit, and will use it on my cycling trip in Europe this year as well. Recommended.
[Update: I have a post with tips on using this unit]