You totally forget there were rules to the contest in those days, no outside help, one attempt only, a make is important (no score on a miss) 5 dunks, (one from below, one from each corner and two from the "sides" above the key.
And you want to compare that with today? where "I missed 15 times but they gave it to me anyway" mini-me win the contest?
Freak show is a better word.
If you see where he is with his head (and no don't count his fro) and you will see he jumps as high as today, if not higher, there is no way to compare plainly, but I am pretty sure that someone who gave many a great player a defeat (he had to actually dunk several pre-contest rounds, they all did, it was not "invitation" like today) who all were interested in a large sum of money for those days, is better then you make it to be. I personally think you underestimate the achievement horribly.