I have a garmin GPS with Mapsource program. You can build routes on the pc, and download them to the GPS in very few minutes. Then on the route the thing beeps .1 mile before each turn with arrow displaying turn direction, then beeps again at 100 yards. YOU CANNOT GET LOST.

If you just wander, you can upload where you have been via the trail left into the pc for future reference. My has vertical speed as well, altitude of course. It is also a good check for your given distances on your computer. It is far more accurate.

When I am alone in strange territory(INCLUDING $$ RIDES where I preload the route), or going with the group on a first time route I use it, otherwise it stays home.

For me this is one of the greatest toys available. I just cannot understand why any biker would want one without the full mapping functions and display. To each his own I guess.