I've yet to find a reasonable size market where Kerrygold, and often President, are NOT available. Sometimes you have to look in the right spot, though - some markets put it with the better cheese products, some with the regular dair products.
I occasionally use Kerrygold for eating, but only certain times. I actually find it somewhere between Land o Lakes Margarine and Land o Lakes regular butter. it Is less salted than American salted butter. I find most of the American brands tend to taste to me more "milk-like" than the European ones, which have their own tastes. When it comes to baking I will ALWAYS use an American brand, usually Land o Lakes or Kates.