I've had plenty of Guiness and lager, and real english and irish ale's not brewed in the States...(Is guiness still an import, I think they actually brew it over here now.)...when i worked 4 years in a Restaurant/brewery that specialized in food and beer from englane, ireland, and wales. Its called "The Shipp Inn" for reference.
We had a chef's exchange with england, and not one culinary expert from england or wales or even ireland enjoyed guiness, its their version of coors or budweiser. They all agree it tastes like shite. However they much prefer newcastle ales, and the house brew.
Its a matter of opinion, me I like a beer i can drink with my meal and not as my meal. If it goes down smooth and doesn't rile the taste buds, its for me. As for pee water, sam adams and red stripe are a tad watery but both definetly still have their flavor. I mean, we are runners here not fat irismen.