I got a virb elite cheap just before xmas, wasn't a great deal more than the bottom
gopro. Theres a review of it
here
I wouldn't say the Virb is massively bigger than the gopro but the format is different which will make a difference to how you can use it. I've got a friend that highly rates the GoPro chest mount for mtb - I wouldn't use the Virb in the same way. I have mine mounted on the bars but then I don't wear a helmet anyway. There is a low profile mount available that looks to be better than the supplied one. Bar mount is solid enough and does the job
Virb elite will as
@T.M.H.N.E.T says connects to ANT+ stuff and if you're just using the Edge 500 for recording rides you won't need to take it along as it will do .gpx and .FIT files and sync them to Garmin Connect. I'm now thinking of it more as a cycling computer that can record video than an actioncam.
My use of it so far has been so boring that I've only looked at a few bits of the videos and had a brief play with Garmins editing software before deleting the files. Footage I like, even bar mounted it doesn't seem to suffer from much vibration. The editing software is nothing fancy but fine for YouTube clips, and it comes with a variety of speed/heart rate/mapping overlays data that it pulls straight off the camera.