Naw, I don't think Campy won.
The Nivex and Spirax designs actually as I can understand shifted a good bit better than Campy. Nivex appeared on many French cyclotouring bikes, especially Alex Singer bikes.
The sad truth is that Campy really goofed on its design. Had the Campy design allowed for the pulley cage to pivot on the axis of the upper pulley, it would have been great. But alas not, and for 40 years Campy rear ders couldn't shift well to the smallest cog when on the big ring. The French figured this out early on (although early Simplex parrelelograms were Campy copies with the same flaw (but at least sprung upper pivots so they worked better).
What Campy rears allow for is easy wheel changes. It is ugly removing the wheel on a Nivex equipped bike. But then, the split rear axle was devised to keep the cluster on the frame during a wheel change. That goes way back in time, well before the Bivalent.
Much of this info is accessible to those who are interested in Jan Heine's Vintage Bicycle Quarterly. There was also a fantastic issue in that publication outlining the early Campy GS rear der that sparked this thread a few issues ago - its not just about the French stuff.
Mike Kone in Boulder CO
> Pre-Campy GS (1951) parallelogram rear derailleurs I found in a quick
\r?\n> flip through the books:
\r?\n> THE DATA BOOK:
\r?\n> 1947, chainstay hung.
\r?\n> 1935, Nivex also chainstay mount
\r?\n> THE DANCING CHAIN
\r?\n> p. 149 - J.I.C. Course was a parallelogram unit (1946-51), but not
\r?\n> nearly as elegant as the Campy design.
\r?\n> p. 150 - J.I.C. Tourism loks like the real mccoy, but chain-stay
\r?\n> mounted. Same era.
\r?\n> So, by and large, it seems fair to conclude that the Campy GS, 1951, was
\r?\n> the first successful parallogram rear derailleur from a firm big enough
\r?\n> to market it.
\r?\n> And it was one heck of a lot better than the plunger units it competed
\r?\n> Still, someday I want to own and use the one that got away: the earlier
\r?\n> Altenberger or later Suntour chainstay mounted units with horizontal
\r?\n> parallelograms. I've only seen the A. once, on an "Altenberger Gruoppo"
\r?\n> Cinelli at Cirque a few years ago. I think 1954, and fortunately too
\r?\n> small for me.