As I write this, I'll be honest, I'm a bit annoyed. I purchased my first GoPro HD Hero2 towards the beginning of the year. It unfortunately got lost in the Tough Mudder run (My own fault!) and I re-purchased towards the end of June.
Why am I annoyed? After spending the best part of £750 on a new GoPro with a lot of the accessories, the replacement model was announced just yesterday, the GoPro 3. Twice as faster but more importantly smaller and lighter. I will however try not to let this shine through in this review!
I've had the GoPro for a few months now and have used it on training runs and mountain bike rides as well as all of the obstacle runs that I've been on. It has taken some getting used to, particularly finding the best settings. I made the investment after seeing footage online and wanting to document my first event Tough Mudder. We also didn't have a camcorder at home and having a young son I wanted to be able to catch some of his moments growing up as well.
For me, the super-wide aspect ratio running 60 frames per second on 1280x720px has been the best by far. Sure, it will do a full 1080 shot but only at 30 frames per second. This is fine for shooting slow moving stuff, but for anything at speed, super slow-mo editing or screen grabs, you can't beat the 720px with 60fps. You should also follow the guidelines from GoPro and make sure you have a class 10 SD card to keep up with the processing write speed. I used a class 4 whilst waiting for mine to turn up and the video was blotchy with parts missing. It's never worth missing the unique and awesome footage it for the $15 or so extra that it costs.
I bought the outdoor edition, but have since also purchase the chest mount, handlebar mount, tripod mount, etc and they have all been great allowing me to shoot anything that I've wanted to. For the obstacle runs, the head mount is the only way to go. The chest mount is ok, but with the natural body movement from running it makes you look like a dodgy first person shooter, and watching the footage can be quite nauseating.