I don't have a GoPro, I have a DriftHD. I like it because, although the video quality is a smidge less than the GoPro, it's 'torpedo' shaped. It looks better, IMHO, on a helmet than a GoPro. It's also a bit more aerodynamic (which matters a lot more on my motorcycle when you're going 70mph and a camera hanging off the side of my helmet can start tugging!)

I've yet to use it on the bicycle though. But I wear it every time I ride the motorcycle. Honestly, just because sometimes I like to look at ride footage. It's kind of cool. But I am sure it'll come in handy should I ever get involved in an accident. It's hard for a drive to say "He was speeding and came out of nowhere!" when I've got video footage of my speedometer, and the driver pulling out of an intersection or turning left in front of me, violating my right of way. Which I HAVE had happen, quite a bit actually. But I've never reported it or forwarded the footage. Maybe I should?

The only exception to that was an OBVIOUSLY drunk driver. They pulled out in front of me after leaving a bar, I braked in time. Then followed them for a few minutes. (not intentionally, they just happened to be going the same way) Speeds changing, swerving, even going all the way into the oncoming lane and touching the opposite white line. Luckily, no traffic was coming the other way as this was late at night one evening. My helmet has two little speakers and a microphone mounted in it, and connects via bluetooth to my phone. Usually for music. But, it does support hands free calling! So using a button on my helmet and "Siri", I called 911 and informed them that a very dangerous drunk driver was on the road and was minutes from a bad accident, and mentioned I had it on camera. The next morning I got a phone call from a state trooper who had arrested him for DWI, said he was way over the limit, and thanked me. And asked if I had the footage. I said yes. He asked if I, if asked, could provide them the footage. I said yes to that as well. Though they never DID ask me for the footage. My assumption is the guy either took a deal with the prosecutor or they just decided there's really no need for the footage if they've got his BAC way over the legal limit. (Unless maybe they were planning on piling on citations for crossing the center line, failing to signal, and other traffic violations he committed 'on camera'. But I'm not sure what the legality of that is.) This all happened when I was on the motorcycle, of course.

If folks don't see my motorcycle with a bright halogen headlight and driving lights, orange cornering lights, reflective gear and helmet, and loud exhaust coming from the V-Twin engine, then they'll never see a bicycle with a little bitty blinking light! I don't think a helmet cam is a bad idea. Though there are some out there who I think invite trouble because they want a good shot.