I always hated lecture and rarely attended lectures, so the transition was easy for me. If you are the kind of person that loves lectures, stays focused and gets a lot out of them, PBL might not be for you.
Pros:
Deeper understanding of material through reading academic texts (IMO, at least)
Making your own learning schedule
Deciding where and how you want to study
Having an investigative, problem solving mindset while studying
Learning how to explain things, ask questions of and even debate with your colleagues on the material
Early exposure to patient cases and working through histories, lab values, xrays, differential diagnosis, assessment and treatment plans
Learning all aspects of a particular problem at the same time - i.e. a chest pain case will lead you to study the anatomy of the chest, physio of the lungs and heart, patho of the lungs and heart, pharmacologic treatment of the possible disorders, etc - all at the same time so it's all connected
You can spend more time on your weaker areas, everything is customizable
You don't have to spend much time in the actual school building
Your learning doesn't depend on the quality of the lecturers
Cons:
You may at times vehemently disagree with the way your PBL group mates want to run the PBL session and this may be distressing
There is little safety net if you fall behind, everything is on you
As you can see, I'm pretty happy with PBL
Maybe others could add more Cons to the list.