By and far, I believe the Therapist Development Center (TDC) has an edge on the critical tools needed to pass this exam. I tried AATBS (testbank) and Gerry Grossman (study materials and testbank) and, in retrospect, can say they were fundamentally lacking. AATBS' clinical vignette exams are simply not representative of the actual test, and their rationales will only lead you into a place of frustration and confusion. With respect to Grossman, while his tests were more palatable, he was too focused on memorization and paid short shrift to developing the actual skills needed to get through the test. I believe using my TDC skills and strategies was the fundamental thing that got me through the Vignette Exam with a greater sense of ease and with confidence that I was passing when I arrived at the end. I recommend TDC highly.
MFT