Have to agree with Frank.
Having had a few units (tomtom rider, navman, etrex, etrex vista, magellan) now own a garmin 60csx.
I use it on the bike, in the car, on foot and sea kayaking.
Not the biggest screen for bike and car use doesn't give voice prompts (don't like them anyway) but a bonus when walking or in cities.
Uses 2xAA batteries or power from car/bike, and takes a variety of maps for road navigation or topographical for hill walking ect.
V good GPS ariel and battery life and buttons aren't too bad to operate when on the bike.
Depends on personal pref at the end of the day but I like the fact it uses off the shelf batteries and is more pocket sized than most ones with a bigger screen and internal batteries.