I was at a local Trackday for some days ago. (2-300 street cars driving on track for 3 days)
And for only 2 DAYS, one stand did sell 36pc of GoPro cameras !! (he was sold out)
I think SONY\JVC have a long way to go if they want to break into the action camera category.
GoPro is handy, easy to operate, lots of accessory, LIVE out, low-cost and a big name.
Think they will stay strong for many years to come