I have had my Edge 500 for three weeks. My wife has had one for about three months, so I have been familiar with the Edge 500 for about three months, but have been using it for only three weeks.
The 500 will give you HR, Power, Speed, Time, Distance, Elevation, and all of the variations of these metrics, ie %grade, vertical feet, etc...blah, blah, blah. It does a great job. They will download to several aftermarket programs. I use TrainingPeaks WKO+3.0 which has a device download built into the program, super easy and fast transfer. Garmin has its own online download with Garmin Connect, I have used it a few times. It is pretty to look at, Connect used to be Motionbased. Anyway, I am not going to get into all of the third party software that the 500 will talk to, but there is quite a few out there that it does. So, that's a plus.
The 500 has a rechargeable battery via USB and wall. Battery life seems pretty good, but I download after every ride and it gets a little top-off.
I like the ability to create a new file on the fly. So you can do a warm-up before a race, reset the unit for a new file, race, then reset the unit for a warm-down. Three individual files, all waiting to be downloaded. You can also delete/view a file in memory on the device. It has a lot of memory, not sure how much, but I have to download after the ride so it is not an issue for me.
It comes with two mounts that work on the stem or bar, so presto you have a two bike set-up right out of the box. There are jelly bracelet looking bands that hook to the mount and secure it to the stem/bar. It looks pretty weak, not aesthetically, weak as if they are going to snap and the $250 computer goes crashing to the pave. So far so good, no problems, and it holds the computer securely in place. No traveling on rough roads or potholes, the unit stays in place. The unit twists off the mount with a 90* turn. Easy Peasy. The bands are simple to take off one bike and put on another, if you have more than two bikes that you are going to use. Remember, two mounts come in the box.
The 500 is sold with a cadence, and speed sensor, and HR. I don't have the cadence/speed sensor, I use the speed from the gps unit, and cadence from the power tap.
The 500 is ANT+ compatible, so it will talk to third party power meters and HR monitors. Here is where I have been having problems with the 500. Since the 500 is ANT+, it is actively looking for ANT+. That means that it is trying to talk to every PowerTap, SRM, Quarq out there in a 100m radius. So setting up your 500 on a group ride can be done, but you just might have to ride a block away. Set it up at home, and whatever you do....DO NOT PUSH RESCAN on a group ride.
I have had the unit drop a whole file on download. Very annoying. Lucky for me it was not a "training" ride. I would probably have worse things to say if it had been. I have the attitude that "if your not gathering metrics, why ride?"
When I have had a little more time with the 500, I will do a long term review.