Jerykk wrote on Mar 5, 2011, 07:19:
I somehow doubt you can reach the max rank within a few hours. In any case, the amount of time it takes you to max out doesn't change the fact that the system inherently unbalanced. Unlockables that affect balance simply have no place in competitive multiplayer games, even casual ones like CoD.

As for unlockable and leveling systems being used to compensate for shallow gameplay, I think double XP weekends like the one described in this topic speak for themselves.