I tasted the 250 from Guiness today. Quite the odd beer. The barkeeps were not enthused by it at all and I can see why. It is the regular stout that is watered down with Irish spring water. It is not bad at all. But it does have a more carbonated/soda-esque taste to it. With a nitro tap it might be even more pronounced. Either way, I am not sure if it is a marketing ploy.