I have the Garmin Vista Color model. It includes compass and altimeter. IIRC, Garmin claims about 30 hours of battery life. I also turn it off between readings except when it's operating on vehicular electricity. Battery life does not seem to be a problem. I also find it much easier to use a conventional compass than the GPS compass.

When I was deciding on which GPS to get last year, I found the Garmin 60CS to be very attractive due to its larger screen, larger memory (56 vs. 28 mb), and easily attached external antenna. However, the Vista case appears to have superior watertight integrity. Sometimes the basics are just too important to risk.

Incidentally, I need to thank Mat. His recommendation to use transparent screen covers was an excellent idea. During my first trip, the GPS worked its way out of pocket and landed face down on gravel. Thanks to the screen cover, the GPS sustained no scratches to the screen.

John