The F-4u1C was considered a killer in the main arena then because...
It was under weight and the new FM today is vastly enhanced as compared to the older FM. Though there are some things I prefered in the older FM. The gun FM is now more realistic as well.
People used to fly around and take pop shots with those guns at unrealistic trajectories and break off wings of enemy planes with just a few hits. I know because I use to fly it also. What made it unchallenging to fight a C-hog was that alot of the people who flew it then didnt really know how to dogfight in it, they just went around and HOd everybody at every chance. A good pilot flying it was difficult to fight, down right deadly because you must matched his every move (so as to prevent his lucky snap shots of death).
Also only 200 were evere made in wwII.
I still hate C-hogs, perked or not.