The Shimano Golden Arrow is a pretty derailleur and the GS is a little rare... I have always liked these for their looks but their performance is lacking and they are much like the very attractive 600 Arabesque in design with no B screw and springs that have a tendency to wear prematurely.
In this era Shimano was chasing Suntour (like everyone else) and these newer models were still nothing like the earlier Suntours in regard to performance... I have retired a lot of old Golden Arrow stuff while the Suntour derailleurs usually just need a light service to make them work like new.
That comparison:
Cyclone MK.I - Beautifully made, outstanding performance, and one of the lightest derailleurs made.
Cyclone MK.II - Does not look nearly as good as it works, one of the best derailleurs as far as function and weight goes.
Suntour Vx GT - My favourite touring derailleur, beautiful, solid and smooth.
Suntour Vx - Short cage version... beautiful, light, and superior to it's contemporaries.
Suntour V GT Luxe - A workhorse... nearly burstproof and a very solid choice and still pretty light.
Shimano Golden Arrow (long cage) - Well dressed but more show than go and where is the B screw ?
Campagnolo Rally - Have no experience with these... but like Campy's other offerings it is a solid derailleur with many fans.
Suntour Le Tech (i've heard good things about this one) - Nice but it is no Vx.