I personally loved my three years at LUISS university. The overall experience is something I would recommend to anyone.
The main campus in Viale Romania is very pretty, with lots of green areas and nice spots to spend your extra time (such as the LOFT, the Language Cafè, a small wooded area with table tennis tables and other amenities, Radio Luiss, and so on). There are drinking fountains at every corner, even two dispensing sparkling water, charging stations (there are also ports everywhere), printers, MacBooks available for students, a tiny movie theater, 3D printers and so much more.
There are only a few complaints I feel I should mention. There isn’t enough room for students to study (not even in empty classrooms), nor at the cafeteria and neither at the bar (in Italy a bar is where you get coffee). Also, parking in Parioli (the neighborhood the main campus is located in) is ridiculous… if you have a car take into account at least 0.30h to find a parking spot, even if you drive a Smart. The university doesn’t care about this at all, offering only very low discounts for garages nearby (still super expensive, about €170 per month), and even taking away all parking spots reserved to motorbikes within the campus (for no apparent reason, as there’s plenty of space).
I cannot say much about the cafeteria since I never ate there, as no one recommended it (I was told that prices are high, quantity is not there, and quality is average), and also because there are plenty of alternatives in proximity to the campus, or you can even get food delivered.