I also have a Garmin 500, and I like it well enough. The GPS on the 500, doesn't necessarily offer much in the way that a "true" GPS would...such as on the 800. But you can upload your rides to the Garmin Connect website and it will paint a Google map of where you just rode...pretty cool feature, I suppose. I like the fact that you can customize the screens (there are 3) to contain which data fields you want to display. My only gripe, is that the HRM has never worked accurately for me...it always shows my HR at or below 100bpm regardless of how hard of an effort I'm putting forth...which in turn, calculates my calorie burn incorrectly. But I've been told that this may have something to do with the set-up and entering my resting/max HR. To be most accurate, I guess you're supposed to do a lactate threshold test, which I'm too lazy to do. So I just pay no attention to the HR or calorie numbers anymore. Other than that, it's a great unit.

Linda