PBL has its ups and downs.
Upsides:
1. If you hate lectures, you'll learn better in PBL. Most of your learning is on your own anyhow (reading, reviewing notes, etc.), so you're just cutting out the lectures.
2. PBL is usually done in an organ systems approach. So you get all the disciplines (pharm, phys, biochem, etc.) related to that organ. To me, it allows a more comprehensive approach.
3. You center your discussions/studying around cases, so by the time you're a junior, you can apply what you know to real life patients.
4. You aren't forced to sit in a classroom from 8 am to 3 pm everyday. So you'll have more opportunities to study when you want, and to live a life.
Downsides:
1. Things aren't spoonfed to you. Rarely, if ever, are any notes from the professor given to you. So you don't know what they are going to ask. To compensate, you learn everything you can from the text. (One could argue this is good, but it generates a lot of stress.)
2. When the topics are difficult to understand, then you may be in trouble. Most professors will basically teach it to you if you can't figure it out. Some, however, will just keep referring you to additional texts.
Overall, I really loved the PBL system at my school. If I had it to do over again, I wouldn't change a thing.
Good luck in school!