I really enjoyed the PBL process but I also understand some of the skepticism around it. A bad apple can really spoil the bunch, so part of the issue is being serious about the cases and holding your groupmates to a certain standard. Some people try to do the bare minimum and have to be called out for it... you take your own education more into your own hands. I did well with this style. I found a small study group of like minded people to discuss the cases and study for the exams and we have all done very well (dean's list, specialty interviews/acceptances, passing boards, etc.).
I must also say that I had a strong and broad background in the sciences and this put me at an advantage. I noticed that my classmates with weaker science preparation from high school and college had a more difficult time getting up to speed. That being said, people passing boards has not been an issue. The way the tests are designed and the way USC implements organized review sessions and provides materials to study for these exams makes up for it. In terms of the NBDE II, that was a breeze for me because I knew all the clinical stuff so well. USC places a really strong emphasis on clinical education like understanding materials, preparation design, lab fabrication procedures, etc.
I really like the flexibility of studying on my time, at my own pace, and with people I enjoyed studying with rather than being stuck listening to a lecturer for hours upon hours each week. That being said, we still receive classroom lectures on dental related subjects. We still had classes and lectures on removable prosthodontics, crown/bridge, anesthesia, and all of the specialties like endo, ortho, and perio.
I am going into a specialty, but I feel like I have a broad range of clinical experience and skill that I know I wouldn't have if I attended another dental school (and I have spoken to friends who attended other schools.) The outside clinics and rotations like LA County, Skid Row, Queenscare, and Mobile Clinic give you lots of clinical experience with patients outside the dental school setting and I have found this extremely helpful in balancing out my education and learning from multiple faculty.
I highly recommend USC for dental school and I am glad I came here. Yes, every school has its eccentricities and frustrations, but I have been happy overall. Yes, it is expensive and will take some time to pay off, but I honestly think it will be worth it.
Feel free to send follow-up questions and I will do my best to respond.