XP balls are stupid in my opinion. We already have so many other balls of stuff flying out of the corpses we create, why do we need flashing marbles as-well?
I think the game should remain how it is, but measure the talent/experience of the player. The web graph is a great idea, and at the end of the day, you'd see your true "exp level". It wouldn't change the way we play, but would add a sort of nice little reminder on what we're good at.