I read a forum thread that said that Pot Limit Hold'em was superior to No Limit Hold'em because it forced more post-flop play so there is more "poker" being played. I think it was the PokerDome show that enforced a PL pre-flop structure then NL post-flop. I'd like to try it sometime, either as a twist on TuNP or on a weekend poker night or maybe during Ryan's mega-deep stack poker experiment night.
I think it would help to avoid 20 chip open raises and introduce more tactics into the game.
At the very least it would be available on Dealer's Choice nights for a round but who would be interested in doing a full night of that to see how it affects play?