I've been looking at the Mobius quite a bit, but was uncertain if the image stabilization would be good enough to capture off-road footage. I like the idea of the Runcam Split as a built-in camera on the front or rear of the bike, and even toyed with the idea of mounting the lens on the chinbar of the helmet. Whether the bike or helmet, the stealth factor would be great!
It seems like the mini cameras marketed to the racing drone crowd have a better form-factor when it comes to our purposes. The cameras offer streamlined bodies, decent image quality, good battery life (or offer capacitors), and many have a variety of lens angles. Hope to test some out this summer to see how they fare on the motorcycle.