Jedi, that's about correct...only I think there's 40 in the class, not 50. I could be wrong though. About 1/2 north american. These are true graduates. Yeah, in the old "system" depending on which university, those with science degrees entered the 6-yr program but Directly Entered into 2nd year. So we're known as "direct entrants."
I'm not really sure how competitive RCSI is in terms of US qualifications. In terms of Irish qualifications (ie. leaving cert), the standard may be slightly lower. However, this doesn't really affect the Irish population, but mainly the foreign ones. (ie. there have been stories before of foreign students with relatively low leaving cert points but the right amount of $$$ gaining entry). In the old system anyway, not too many Irish gain entry into RCSI.