I just finished my freshman year of college and I can say that living in a quad (3 other roommates) honestly sucked. I would say that out of the 13-14 times that my girlfriend visited from back home, I got to take my time and fuck her deep/long a maximum of three times, otherwise it was always fucking hard and fast to get it done before they got back from classes.
On the other hand, living with three other guys meant that they saw my junk on more than one occassion and word got around the dorm (smallest one on campus) that I was decently hung (being uncut was also a novelty since I'm in a US university) and I was able to fuck a girl on the side who lived in a single on the second floor. Positives/Negatives I guess.
Also, trying to find time to jerk off in a quad is non-existant. When I felt the urge I had to stay up until 2-3 in the morning until everyone was sleep and i'm sure at least one of them woke up on occassion but never said anything.
As for other kids in my dorm having sex, we're a pretty liberal campus. The RA on the second floor had a little dish of condoms sitting outside of her door. And sometimes we would laugh because if you sat in the common room of our dorm late at night, you could hear the headboard of a bed banging against the wall in one of the two rooms situated above the common room (we never really found out which one).