Garmin makes the Edge 500 for people who are overwhelmed by the 800, whether it's the sheer volume of available data or its size. The 500 is a better choice if you prefer a compact package on your handlebars, and it delivers a big dose of information that you can readily access as you ride; leave the brain pain at the office with your spreadsheets.
The 500 is a great stand-alone bike computer that allows you tremendous flexibility in terms of what you track on your ride. There are two fully-customizable ride screens, each holding up to 8 lines of data. The 500 won't tell you what data should go with other data; you can choose the setup on your own. You want to run temperature and cadence? You can do it. As the unit comes, you can get times, temperature, altitude, gradient, speed, cadence, and all the combinations you can think of in terms of averaging. You can pair up the 500 with any ANT+ enabled power meter to add power data as well.
The 500, while GPS-enabled, does not have mapping capabilities on the computer, so you can neither see a map nor have it dictate a route. The unit also doesn't have a virtual training partner feature. It will, however map your coordinates so you can see the ride on your computer when you're finished up.
The 500 works with Garmin's own Training Center program. The program is a free download from Garmin's website and is compatible with PCs running Windows XP or newer and with Intel-based Macs running OS X 10.4 or later. The data can also be uploaded to the Garmin Connect website for free, and to Map My Ride, Strava, WKO+ and TrainingPeaks.
This version of the Edge 500 comes with a Garmin heart rate monitor strap and a Garmin GSC10 speed/cadence sensor for the left chainstay as well as the requisite magnets and zip ties. The battery in these accessory units is field-serviceable; each runs on a CR2032 watch battery. Two handlebar/stem bike mounts are included as well as an AC charger, a USB cable, a paper quick start manual, and an owner's manual on CD-ROM.
The Edge 500 measures 1.9" wide by 2.7" high by .85" deep (4.8x6.9x2.2cm). The display size is 1.17" wide by 1.44" high (3.0x3.7cm). The display resolution is 128x160 pixels. The unit is powered by a rechargeable lithium-ion battery that will get up to 18 hours on a charge. Claimed weight of the Garmin Edge 500 is 2oz (56.7g).