Is exported whiskey different?

Unless you are looking for a special bottle that is a difficult-to-find whiskey blend, it’s best to pick up Jamesons at the Duty Free Airport shops on the day of your return flight. The shop usually will deliver the bottle to your flight and it will be kept safe by the flight attendants until they give it to you upon your arrival back in the U.S. one Liter is allowed duty-free.
If you have a connecting flight in the U.S where the 3 ounce liquid rule is enforced, the whiskey must be in special sealed bag called a Steb ( Secure, Tamper-Evident Bag) that you can not open.

It is exactly the same wherever you buy it.

They do make a couple varieties that are only available directly from the distillery. Crested 10 is one.

Of course buying some direct gives you something to talk about with those friends and neighbors. ;-)

The standard Jamesons is the same, but if you tour the distillery, you will likely be able to find different blends, maybe cask strength or single barrel bottles.

If you buy in shops in Dublin, the whiskey might be the same, but the labeling will be different.

I have found that after three or four whiskeys it is difficult to tell them apart from grapefruit juice but then I'm a lightweight.

I think you can't go wrong buying it anywhere....

One especially can't go wrong if they substitute Bushmills for Jameson.

I could be wrong, but I was told by a shopkeeper that Bushmills is Orange and Jameson's Green (therefore, be careful where you order it).

It depends on where you live, but in Oregon, Irish whiskeys are uniformly cheaper at home than in the duty-free store or in-country at shops. We usually buy a bottle of a local at Lidl or Tesco to sip during our stay.