You are rigth with the late seventies and eigthies sports watches, they all had one. I remeber the 222 from VC, the Oysterquartz from Rolex, the Santos galbee from Cartier, the St.Moritz and Monte Carlo from Chopard, Seamaster Polaris from Omega and the Riviera from Baume&Mercier. They are all in the same niche, but they are not "so inspired" from RO or Nautilus like the GP. I think this is the difference and you can see it.
Of course, it is a great watch, because a great genius is behind it.
Best Walter