AH so you mean PBL vs traditional?
what i can tell you is this---purely PBL is pretty useless in my opinion. you walk into a subject blind, using textbooks to learn everything/figure everything out.
PBL in conjunction with traditional didactics. yea, i can see that working
friends at PBL schools have told me the same--they cram for each PBL session and don't really get much out of it. i suppose it does give you more time to focus on clinical classes, so that might be a plus