Blondcookie.
I agree with your assessment that carib. schools use this as PR but i defer to the scores those students get who are taught in the system which the USMLE tests. Your step scores directly relate to the residency you may get. Your suggesting that "any question on pathology is just that" is totally fallacious. Anyone who has studied standardized testing will tell you that and research backs it up 100%. Taking a standardized US test is 60% knoweldge and 40% understanding the way questions are asked and learning how to "test take" for the USMLE. The MCAT is the exact same thing hence the incredibly strong coorelation of strong MCAT scores to strong step 1 scores.
While i personally wont goto the Carib. I do see why many would and how it could be of benefit to them. It is in the best interest of the carib. schools to have their students do well on USMLE to increase their rep and therfore students ergo profitability. There is no such pressure on UK or Irish schools. They will go out of their way to make sure you do well on the USMLE including prep classes where others have no invested need to.
You have to remember that these students also spend their entire 3rd and 4th year in the US system for clinical time. They gain a LARGE advantage when it comes to US medicine, the USMLEs and residency oppertunities over other IMG's. Making contacts in hospitals with residency programs will go a long way to attaining residency advantage both within the match and outside of it. As someone who works in hospital and sees this first hand i can assure you its true.
While i agree that the training is what is important I would also suggest that you might consider that life is all about who you know not what you know, including medicine (i know i work within the system). making contacts would be more important than the "quality of education" if your goal is to get back to the USA as fast as possible in the position you want.
In talking to many US students who have gone to Ireland for medical school their biggest weakness has been the USMLE scores. Many come back as family practice or IM docs (not competitive) just to get back to the states. The 97-99% range noted by a previous poster is not the typical score for UK/Ireland USMLE test takers.
There is much more to consider when taking the Carib. vs UK/Ireland choices into account than "prestige of school". As with any education, you get out of it what you put into it. Many incredibly excellent physicians have come from state MD schools in the USA and many weak ones from Ivy league schools with greater reputations.
WHERE you went to school is not nearly as important as the effort put into becomming a great physician is, the information is all the same.
References:
http://www.aamc.org/students/mcat/research/bibliography/blueg001.htm
http://www.usmle.org
A comparison of statistical criteria for setting optimally discriminating MCAT and GPA thresholds in medical school admissions.
Teach Learn Med. 2005 Spring;17(2):149-58.