I've got a GoPro Hero, a Cycliq Fly12 and a Fly6 (rear camera).
The GoPro is a better action camera if I want to use it in a RR or a crit or snorkeling in Hawaii or in the pool at home, etc. BUT it has limited battery life. Around 2 hours. I do lots of rides and races that are longer than 2 hours.
On the other hand my Fly12 will do something like 10 hours of 1080p video. It's too heavy for using in a RR, but if I want a "in case something happens" front camera I can't see how you can beat the Fly12. No to mention it's got a 400 lumen headlight for when you need it.
Simlarly, the Fly6 is good for around 6 hours of riding and has the built in flashing tail light that you can turn on and off.
In both Cycliq units you never need to worry about filling up your SD card as it will start overwriting the old files when it fills up. They also have an incident mode where if you fall over it will record for 30 minutes and then turn off. This way, if you have a small SD card and say got hit by a car early in your ride it won't just keep recording nothing until it overwrites the accident.
If you want a good combination of "don't hit me lights" that record video "just in case" I think it would be really hard to beat the Cycliq units.
For camera quality, the Fly12 does up to 1080p 45 FPS and the Fly6 is 720p. The Fly12 does good video, but isn't on the same level of camera quality as the GoPro. It also isn't as versatile in that it doesn't do stills or burst mode or higher frame rates like the GoPro
For me, I use the Fly12 as kind of a daily driver that all I need to do is charge and if something interesting (or bad) happens on a ride I'll have captured it.
Kevin
http://kevinmetcalfe.dreamhosters.com My Strava