To pull PBL off, you need enthusiastic and talented teaching (yes, teaching) staff who are prepared to spend lots of time waiting for students to see the light. Sometimes, that can be a very long wait indeed. Similarly, you need open minded students who are filling to abandon years of spoon feeding from secondary education. (Primary education in the UK is quite good now, lots of PBL - secondary is where it all goes wrong).
Maybe a little PBL for appearances sake is fine (an hour on Sunday morning followed by a slap up lunch) - just as long as it doesn't take over your life.