It was only snobbery and sponsorship agreements that kept the professionals from tossing their Campy NR derailleurs and swapping in a Vx or Cyclone as they were lighter and shifted better... a lot of the old Campagnolo kit is beautifully machined and very solid and Berto said that the best thing about the Nuovo Record was that it shifted poorly but was so well made it would shift poorly forever.
It seems like many of these old Suntours are still shifting beautifully after more than 30 years which is like forever for some people and it has only been with the advent of carbon fibre that Shimano and Campagnolo have been able to make lighter road derailleurs.
The Mk1 Cyclone short cage is something like 185 grams and GT version is 195 grams... these are lighter than the Mk2 Cyclone series.
When I bought my first road bike I could have bought a Campy equipped bike or a Cyclone equipped bike... the old pro who ran the shop said the Cyclone would make me much happier and save me a lot of money and some weight... he said it was some of the nicest gear he had ever used.
My love of Suntour started over 30 years ago and started with the Cyclone Mk2 and I find I like the older variants and the Vx even more because it also looks as good as it works.