I'm from the UK, and will not touch Guinness here either, it does have a bitter after taste

Having said that, you can find really poor Guinness in Ireland also. I've drank Guinness in Belmullet that tasted like washing up liquid, which it most probably was...

The quality is down to the maintenance of the pipes etc, the way it is stored, and of course, poured.

A good pint should leave a 'rings' around the glass, and be wonderfully smooth with no bitter after taste. However, on my visit in September, Guinness were introducing new 'sculptured' (for want of a better phrase) glasses, so that measure of quality could soon be at an end lol

The Roadside tavern in Lisdoonvarna is a wonderful pub, good music when I was there, but avoid the Murphys in that pub, possibly the worst drink I've tasted anywhere lol

Great for making Stewed Beef Casserole but too bitter to drink straight. Mix a glass (1/2 pint) of Smithwicks with a bottle of Guinness in a pint glass for a Black and Tan... If you get a strange look just explain you are going to drink it and then send it where the name belongs. (Black and Tans were British Mercenaries employed by the RIC (Royal Irish Constabulary) to keep down the Irish Rebellion in 1920)

Draft Guinness in a can actually tastes more how Guinness used to taste like than the flash cooler compliant draught from the pumps.