I have a Foretrex 101, and love the little bugger. I strap it on to my wrist, and there it is throughout the trip. I like to use paper maps, and then re-check my location with the GPS. So it's normally just there as a backup, and a watch. It was a necessity once when I got lost in fog though (fog rolled in while I was at a spring pumping water). It got my back to camp, well at least to within 50' of camp where my buddy's voice guided me the rest of the way.