I bought a Garmin 405 CX GPS watch mainly for the heart-rate monitor. Seems like that's the only thing it's good for. I ran a 13k trail race 5-5-12 through an open canopy forest (leaves not fully out). The 405 repeatedly lost satellites. I thought I was doing good...the watch said I went 5 miles...when it said I went 5.25, I past the 4 miles marker. What a kick in the head! When I went past the 6 mile marker, the watch said 7.60. I said screw the watch and stuffed it in a pocket. That's my latest experience with it.