I attend UCD.
Dublin is definitely a great place to live for 4-6 years.
Match stats are variable among the universities but from what I can see RCSI & Trinity consistently do the best.
The instruction at UCD is pretty good, overall. But, UCD likes their curve so don't expect to come here, work hard, and get all As. It won't happen. Too often it feels like UCD picks their grades out of a hat. And there aren't enough objective tests (MCQ) to compensate for subjective marking.
UCD also does not do much to help with USMLE, it will very much be self-study, and the summer after your second year is abbreviated due to entering the hospitals at the end of 2nd year.
The university is incredibly disorganised.
Overall, I find the course good, but not great, primarily due to random grading practices and it would be nice if there was more support for USMLE, and more time given to prepare for USMLE over that 2nd summer. Especially considering roughly 1/3 of the class will take the exam.
Another thing to consider is what US/Canadian medical schools is the Irish medical school affiliated with? It is becoming increasingly common for US medical schools to only allow you to complete clinical clerkships if your international university has a preexisting agreement with the North American university. From what I can tell is Trinity & RCSI have a lot of affiliations. UCD, UCC, and NUIG not so many.