The last revision of the software added a lot of gravity to characters so you can't juggle them forever. In some ways it became less fun with certain characters as a result but the game became more fair.
There were instances that after blocking kano's ball or raiden's dive a character like scorpion could do almost a full life bar of damage with huge juggle combos. There was also a way to juggle someone against the wall infinitely with the characters that had the quick jump punches (cage, raiden, kano).
My favorite rev was the one that still had the floatier gravity for juggles and also had reptile as the hidden character you can fight in the pit. I think it was rev 3.0 or 4.0. whatever was a full rev number lower than the highest one.