I agree, it tastes better on the other side of the ocean, however, a major beer distributor in Memphis told me all kegged Guinness in the US market originates from Ireland. The taste probably has something to do with variable shipping conditions - can't be all that good for beer.

And oddly, all bottled Guinness for US consumption is brewed in Canada. All the bottles I've seen bottle read 'imported', but no mention from where.

Slainte yall,
steve