Well to be perfectly honest with you I am more into how the external spaces are treated in university planning/architecture. Because that is where the students spend a larger portion of their time. Louis Kahn believed that these corridors and so forth, would be like class rooms in themselves where students would learn from no teachers - but from each other - rather than long narrow sneak passages as he called them - normally what is called for in educational budgets.
Notice that nice new space created in front of the new MOLA student centre building - grey brick one, horizontal building. That new space works well I think and ties in the old existing sports hall, pub or whatever, which was quite isolated before now.
MOLA have done a nice little DIT student residence building up at Broadstone, which should also be nice. I have seen the new buildings you are describing, the new Lab is indeed a good effort and commands the space around it nicely - but as you are possibly familiar with in Trinity college campus, new developments always seem to be a mixed bag - with some excellent examples like Arts block in Trinity and some trully awful attempts - owing to lack of budget etc, etc.
It is as if they break the bank on one development, and then build a couple of cheap-o's following that one great building.
I am not really a big fan of the O'Reilly hall in UCD - not because of the building itself as such, but rather the lack of an attempt to deal with and create exterior spaces, like the new student centre does. The main boulevard type of space in DCU isn't at all bad either I don't think. To be honest, I find the UL campus a bit all over the place and lacks any clearly defined grand central space or avenue. Despite all kinds of buildings and investments down through the years, and attempts at making it better. Plus the campus at Plassey doesn't seem to suffer from any problems of vandalism or other difficulties like Trinity college would be exposed to.
What UL campus definitely lacked is a good architect with a vision.
Similarly with the former RTC's, Institutes of Technology around the country. But I think that main 'mall' type space in DCU is alright. In Bolton Street, there was no opportunity to make a good external space, so they opted instead for a grand atrium idea, which is worth visiting. In Angier Street there is a grand central courtyard, which isn't even used, and very little other gesture towards public open space. In Kevin Street, nearby, they have tied together a mess of buildings quite favorably with a nice new hard landscaped courtyard now. Worth taking a look. You should try the little entrance on the side street, which is the one most used by the students now I think. Making the front entrance a bit underused now I think.
I have not been to Cathal Brugha Street in ages now, but I wouldn't expect much out of it really. MOLA seem to have a fine portfolio of educational projects at this stage, have a look here:
No attempt there is made to sell the UCD student centre project though - but other projects are a little bit better featured.