Hi! Sorry about the delay.
For a big class, I do feel I have gotten to know a good number of my classmates.
However, the beauty of a large class is that you are constantly meeting new people and learning more about the ones you are friends with. We hang out a lot (go out to dinner, bars, chill) and I find myself surrounded by a great group of people. Of course this is dependent on each class but from what I've seen of the older classes, they have a similar feel.
As for PBL, we don't exactly do that. We have TBL (Team Based Learning) in place of quizzes sometimes, which is basically a group quiz, broken down into two segments: the first concentrates on basic science and fact-based questions while the second segment focuses on clinical vignette-based scenario questions which are made to be more nuanced and entice discussion. You're assigned your group at the beginning of the year, and the entire class is broken down into two big TBL times.
So the difference here is that we are provided the information for TBL prior to sessions in the form of normal lectures and assignments. PBL, you are basically teaching yourself these lectures from what I understand.
As for my take, I do think it's a fun way to mix up how we apply our learning compared to traditional quizzes. However, it can be frustrating in that their delivery seems very cumbersome when professors administering TBLs feel the need to go through every single answer choice of every question and decide why it's right or wrong. They also do take up a healthy chunk of time during the day. Overall, I enjoy it.