My new (used) Edge 500 just came today. I just got back from a ride with it.
Love it!!!! My Bontrager Node 1 computer was pretty decent as far as computers go.... But the data this thing harvests is way better!
So glad I bought it.
Works flawlessly with my Bontrager speed and cadence sensors too by the way... Really nice not to have to buy new sensors.
I know the GPS does speed as well, but if you are in an area of weak satellite reception there can be some gaps.
I have a Trek and they have the integrated sensors in the frame so it is nice that those sensors work with the Garmin so well.