I have a Garmin Quest and older Streetpilot III. The Quest is really neat with color, auto-routing, and voice, which is why I gave it to my wife. The SPIII, although monochrome, has a much larger screen that's easy to see on the bike. The buttons are easy enough to use with gloves (except Gerbing gloves) and mounted on a RAM mount with power from the bike, it's a great setup. I don't necessarily use it for finding my way, more for keeping accurate track of time, speed, and mileage.
