Not strange, in asia you see a lot of these "cute"themed stuff. Don't be surprised if next version is an "Hello Kitty's" one.

" GPS which is useful if you use the GoPro 5 as a dashcam, "
Nope, speed overlays are not for dashcam, they can be used for action sport as ski, bicycle/motocross and countless other.
Sony got there first 3 years ago.

on top of those 2500$ have to consider the insurance for the subject should he fall from the platform into the chopping rotating camera...

been done already, with a cheap ceiling fan...
https://www.youtube.com/watch?v=wTQjIZR6xHA

Not only the chronos offers "cheap" highspeed slowmo
FPS1000 http://theslowmotioncameracompany.com/#Products

"..and the competition simply has not remotely caught up..."
Oh, Come on..you must be kidding (or living in a gopro marketing bubble)
Sony action cameras have waterproofing out-of-the-case and overlays since YEARS, and their Optical Stabilization is superior to gopro's (not talking about bitrate, 100 vs 60).
Even Garmin with their latest offering is at worst on par with the GP5. Only the session (but with big drawback like a fixed battery) has some valid points.