I don't want to end up with fiat on mt.gox that takes me a month to get out. Besides, often enough bitstamps lagging has kept me from making hasty trades, forcing me to ride out an upswing. Think of it as enforced trading discipline  

Besides, fees at bitstamp are about half of mt.gox, and the whole enterprise seems to be run way more professionally. There is a reason both fiat and bitcoin at mt.gox are going down (I think of the Dwolla issue more as a catalyst to get that shift moving).