Just played a 3-player game with treasure maps (for those who haven't seen seaside, treasume map is : trash this card and another treasure map, and gain four gold cards on the top of your deck.)
It wasn't so much the treasure map that made it crazy: it was all the cards that made it easy to pull the treasure maps from your deck: haven, warehouse, wishing well, scout, cellar, and I think one more that I forget. The treasure map cards all got bought up in the first two minutes, and every single pair was redeemed--fastest game of Dominion I've ever seen.