I come from a small liberal arts college, and I knew that I wanted something different at a college with 30000+ students. The experience turned out to be very different in many senses. Back home I only go to the dining hall, but here I do groceries twice a week and learned how to shop economically. The lectures at my home institute are an average size of 15 people, whereas here the lectures are taught in huge classes (all of my classes are about 60 people but I know there are much bigger classes in other departments). The accommodation is nice--I share an apartment with three Americans. We have a common room/kitchen, 2 restrooms, and we each get to live in a single. To me, the college community here is loose, but from that arises a stronger sense of independence and anonymity, which can be a good thing or not depending on what you want.
I am taking one studio that counts as 3 modules, two other architectural modules, and one module from the archaeology department called Discovering Ireland: Landscape and Heritage. The studios here are BRILLIANT. There are 60+ kids in my class and we are divided into 5 groups, each having 2 tutors. The tutors here teach part-time and all work as architects. The studio is divided into several components: drawing & making, desk critic (led by your group tutors), and presentation and general critic. They really teach you how to look at things like an architect, and draw things precisely/consistently, and the critic here is very informative. I would give 10 stars solely to the studio, but 6 stars to the academic life here in general. I personally much prefer the small and intimate classes back home, The modules I took here tend to be disorganised, and you get graded solely on one or two major assignment throughout the module. This can be scary when what's expected from you is unclear. The course load is pretty manageable and I almost have every weekend free of work. The students here are expected to decide their own workload and study independently. I could have learned more if there is a list of must-dos in the modules, but then I would not have this much time to explore Ireland and its culture.
The L&H soc here does amazing debates and I highly recommend everyone to check it out at least once. Every week, debaters from and outside of UCD and offer their opinions across a variety of themes. The debate chamber is set up like the British parliament and the debate scene is huge. I don't have time to find out about other societies due to the isolated location of the architecture school and its busy schedule. I use UCD's sports facilities quite often. The gym can get crowded in the afternoon, but there are plenty of space in the morning and evening. They also offer physical assessment and can advise you on your fitness goals.
The centre for study abroad is a great resource for American students. They do trips in Ireland/Northern Ireland once a week or every two weeks and they are completely free! I couldn't speak enough about how I appreciate them since living in Dublin is pretty expensive. All you have to do is to sign up. There are also movie nights/Thanksgiving dinner/test prep pizza party and stuff.
The UCD campus is not particularly charming for having huge grey concrete buildings, but there is a lake in the heart of the campus and you get a nice vibe from the community when you walk around. It's set in the suburb, but getting in town is easy. There are multiple bus stations that take you right to the centre of Dublin within 30 minutes. Some people find the transportation expensive (a round trip to town by bus is 5 euro). I do like to go into town, and Dublin is such a compact city where everything is within walking distance.