My VIRB Elite arrived yesterday from Amazon, so I mounted it on my MTB and took it with me today to record the ride. I encountered a few problems along the way. At about 15 minutes in, I dropped off the pavement onto a gravel road, a drop of about 3 inches on my full suspension Cannondale Rush. The VIRB didn't seem to like the impact, and restarted. (As I found out later, it lost the first 15 minutes of video.) I started the first climb, then eventually reached the top and started descending. The road vibration from the gravel road naturally picked up as my speed increased. A little ways into the descent I noticed that the viewfinder was frozen and the record light wasn't blinking. I stopped and held down the power button until the VIRB restarted. (Later I found that the VIRB had lost the GPS data for this segment, although the video was still there.) From here until the end of the ride, the VIRB behaved itself. I stopped a couple of times at overlooks to remove the VIRB from the mount (easy with gloves on) and shoot some stills while the video was still running (pretty cool). The stills came out fine, although with the overcast skies and the leaves all down, there wasn't much point to actually taking them.
So when I got home, I started VIRB Edit on my Mac Pro and connected the VIRB. That's when I found out about the missing first 15 minutes of video, and the missing GPS data for the next 24 minutes (the VIRB stores videos into 24 minute, 4 Gb chunks, so for my 1:42 ride with 15 minutes lost, I had 4 clips). After VIRB Edit retrieved the clips from the VIRB, it offered to let me add GPS data to the first clip. I used the .fit from my Edge 800 to do that, but that exposed another problem. The synchronization done in VIRB Edit is about 15 minutes off, so it was showing the heart rate, altitude, and speed (and the position on the map) for about 15 minutes before the actual video. (The VIRB itself doesn't seem to know about daylight time; at the moment it's showing 2:14 when the actual time is 1:14 EST). Of course, that's only a problem for that one 24 minute clip where the VIRB froze and lost the GPS data for that segment. The remaining clips use the VIRB's own GPS data, and so is accurate. On the other hand, the VIRB doesn't seem to have actually connected to my HRM (Garmin hard HRM belt) and maybe not my Tempe, even though I asked it to. The HRM was working (the Edge 800 saw it the whole time). Don't know about the Tempe, since the 800 can't show it and I left my Fenix at home. The video is displaying G, speed, and altitude, but not HR or temperature.
So. Minuses: the VIRB glitched twice and lost data, both video and GPS. Not good. VIRB Edit didn't synchronize the video and GPS data from my Edge 800 properly. Pluses: the mount was easy to use with gloved hands. Video quality is good, although stabilization doesn't seem to work very well on high speed (25 - 30 mph) descents on gravel roads. The ability to take stills while recording video is a big plus, although the stills are small (in 16x9 12 M pixel mode) compared to my Pentax Optio, which I usually carry.