I actually feel that the game has SUFFERED for its attempt to balance Aliens/Predators/Marines as equal creatures.
I agree. A game shouldn't be horrendously unbalanced, but there are cases where there is an inherent imbalance exists. Like this game, where the three classes are totally different--it ruins the experience to try and make them equal in all respects. But then, I suppose you'd need another way of determining a "winner" instead of straight kills for a game like this.
At any rate, I loved the single player, didn't play much multiplayer.