From what I understand, a benefit to non-eu nationals applying to irish med school, is that they're not in competition with irish school-leavers or eu school leavers. This is because eu nationals are applying for places covered by the governments free-fees scheme. Last year, between the 5 medical schools, there were approximately 300 places for eu nationals, of the 700 in total.
This would definitely increase chances for non-eu nationals, although many north american applicants hold undergraduate degrees. Usually the high school leavers are accepted into the 6 year courses in RCSI, UCD, and NUIG. Since UCC and TCD only offer the 5 year course, competition is higher for non-eu nationals without undergraduate degrees
I knew two guys from canada who both got into the 6 year course in RCSI, and they've been best friends since they were 5 years old! It's great when stuff like that happens.
Best of luck with your application