Looks like they're copying the SJCAM M10. Which, BTW, is $80.
The Hero is nice in that it's waterproof without a case. Still, $400 is insane these days for a cam like that.
I'm sure it has outstanding video quality, but most people using it on a bike don't need that kind of quality. It's like buying a Hasselblad to take vacation snaps.
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Work: the 8 hours that separates bike rides.