I'm starting M2 at a nearly 100% PBL school and, I have to say, it's deceptively effective at teaching. Will you learn the details of every lysosomal storage disorder? No, but you'll learn the biochemistry around them well enough to have coherent conversations about pathways with clinical metabolism docs. You'll learn a prototype disease of that type really well, including the key enzymes in that area and how to differentiate it from similar disorders. You'll learn how to think about those issues in context of a patient. And then when you go back and try to memorize all of the other ones, you'll find that they slip right into your memory because you already know the hows, just not all the specific names/details. Knowing me, I'd probably forget the details by the time Step study came around anyway, so it's not really a loss.
The thing with PBL based learning is that it happens kind of naturally/gradually, and in a less rigidly organized way than lecture/memorization. So it's easy to feel like you're not learning as much. But when you look back, I think you'll be surprised what you know.
The way I prep is to find the textbook section on whatever the case is on, and read it. It's best if you read the whole section here, including related/similar disorders and physiology/path, if you have the time. Then, for more specific questions and details of the case, I look at primary literature. Sometimes it's easiest, if the question is super clinical, to go to UpToDate first and use their citations/info as a jumping-off point.
