I use TBL in my speech classes at a community college. I am not 100 percent with everything TBL, but the general format/concepts I use (for example, I don't do team member evaluations because they have failed miserably for me - I need to take the time to adjust and make those work better).
Sometimes TBL has failed due to drops, poor classroom community, students who feel they are being treated like "high schoolers" because they are being asked to do group work (although I let them know this is a tested, researched, validated and effective learning method)
BUT
overall, it is highly successful.
Rachel Murdock