Salary caps do seem to make for parity in the sports leagues that use them. Your medium size market team has a legitimate chance of winning a championship at some point in your life. The trade-off is that you never get to see the best players in the world playing for a championship. You see one or two of the best players on each team, and whatever other players the team could afford under the cap.
I wouldn't want there to be a salary cap on the company designing my next laptop.