You know what one of the many camera companies need to do is separate the lens from everything else.
I'm considering the Liquid Image goggle cam becuase they don't have the camera sticking out there to get damaged. As hideous as many say the goggles are, I'll take the trade off of functionality.
I might F up a regular helmet cam wiping out, or beat the crap out of it unexpectedly getting into an area where tree brances can smack it.
Same thing if I were still dirt biking.
Separate the camera; it's smaller and less protrusive. Have a length of wires that can be ran down to my inside pocket in my jacket where the battery and everything else can be.
There are a couple of reasons why that doesn't work well. The main reason is that you usually want a fairly direct path for light coming from the lens going to the sensor.... and for quality reasons you typically want as large a lens and as large a sensor as is practical.
I haven't seen the goggle camera that you mentioned, but I doubt it has the quality of the larger POV cams.