Carslaw can be great or horrid depending on what's happening outside. I know of days where it was nasty since there was no AC inside, but you kinda get used to it eventually (I've had at least 1 class every semester in there for the past 5 semesters so maybe I'm biased). Lecture halls are fascinating, because there's entertainment in the desks if you're zoning out.
ABS has nicer whiteboards (try getting a tute there next sem!) and lecture halls, but it's AC'd a bit too efficiently
Education building is cool too, and it's close to Manning as well, but it's pretty popular for those reasons
John Wolley is ok, but the lighting and stairs combined with distance from other facilities is a bit of a downer.
Mereweather is a lot like Carslaw lecture theatres, but with better AC
Nanoscience/Physics Hub is probably the best classroom/lecture theatre, but the only negative is you can't eat in there
Can't go without mentioning the Quad - it's cool for the aesthetic but they should have clearer instructions to get to classes, and reception can be a bit crass in the higher levels. Great for exams tho.
Tl;dr- aim for classes in the newer buildings if you like nicer facilities, but you will live if you can't score any classes there (my negatives aren't complete dealbreakers afaik)
