I have the 500 and I love it! I used to use a Cateye V3 and didn't understand the need/want for a Garmin. Now that I have it- I couldn't live without! I love being able to upload my data and look at it- see cadence,hr, speed- route, temperature outside. etc. Really helps give a good overview of your ride and helps gauge not only progression but how you are feeling each time(and did you need to fuel more b/c heat got intense,etc.)