This all makes a lot of sense. I really do think it can help you retain more material. My only concern is the sheer amount of reading and pacing of it. In undergrad I would read basically 1 textbook chapter per day (40-50 pages) and that was it. It would take 3-4 hours to do and then I would review notes from class. How much reading do you have to do and how quickly do you have to do it?
It starts slower, and picks up. At first, you do anatomy, which is lecture with some reading. Towards the middle-end of anatomy, you start PBL, but since you're also taking anatomy, you read stuff that ties into the anatomy that you're studying and they reinforce each other...
Once anatomy is over, towards the end of 1st semester and into 2nd semester, you might have to look at 3-6 chapters, but you have a day and a half, at least to do this.
Some of the chapters are quite short also. Others are really long and difficult, but it's very doable. It will definitely be faster paced than what you did in undergrad, but that's par for the course in med school. By the 2nd semester you're probably somewhere around 5-10x the pace of the average pre-med undergrad pace. It is like drinking from a firehose, and it's all a blur.
You have 3 PBL tests each semester (at least we did), and first year, you'll probably average around 25-35 chapters per test...ish. Very doable, but unless you have a photographic memory, you'll want to read most of these chapters 2-3 times. I kept a spreadsheet of what chapters I was studying for the test and how many times I had read them, to keep it straight. They're not assigned, your PBL group chooses them based on the case you're working on. So, an MI case might get 3-4 heart physiology chapters, heart anatomy, heart embryo, heart histology, heart pathology, biochem of mitochondria, and HTN drugs...or any combination of the above, maybe not all of them...that's more of a 2nd year amount. By 2nd year, you'll have read most of these chapters for tests before, so if you get a heart case 2nd year, you'll do all the ones you did before, which you probably will barely have to read, plus the ones you haven't done.
I should add that many people don't read much at all, and instead opt for things like the Kaplan lecture videos (with or without supplemental readings from real books or review books). The success you have with this depends on your own learning styles and abilities...some people do ok with it, others bomb because the review courses don't cover quite enough material, but I've found the review stuff to be a good starting point to build on.
It's complicated, I know...but it's a good system, and it works. You're just responsible for your own education. Some people don't handle that responsibility well, but most do very well.