I wanted a GPS to do it all. Kayaking, hiking and auto routing on the road. This is it. I got the USATopo, and Auto Nav kit. Easy to learn and use. Extremely accurate so far. Unit can hold a lot of map data, I have loaded Streets and Destinations and Topo for virtually all of central and northern California. The unit will float if necessary, maps are readable in sunlight. About the only improvements needed would be better topo maps (more detail), and eventually the ability to expand on-board memory with SD or other flash memory.
Overall excellent piece of gear, good battery life, etc.