I prepared for the exam by doing all 550 questions (9 exams of about 60 questions each)in CF_BUSTER from http://www.centrasoft.com/ and by doing all the questions from Ben Forta's study guide, all in one day. I had read the BF guide a few months ago.

After each CF_Buster practice exam, I reviewed in detail each item that was wrong. Same for the Ben Forta guide. Be aware that there are some questions in each of these exams which have either wrong answers or misprints... after shaking my head over them, I tested the question and confirmed that the printed answer was in fact wrong. There are very few of those, but it can be frustrating. Next day I walked in to the exam and got 57 out of 60 correct in about 25 minutes.

I would say that CF_Buster has too many over-simplified questions.... such as choosing the right answer where CFPARAM is correct and CFPARM, CFPARAMETER, and CFPARMSOMETHING are not correct. This just asks you to figure out the right spelling for the tag. However, there is a lot to be gained by using CF_Buster due to the repetition of concepts between exams. For example, each exam has some core questions that are slightly different between the 9 exams. This reinforces the concept, but may lead to boredom.

The Ben Forta study guide is much more challenging and IMO tests more appropriately for good developer skills. If you nail the Forta book, then you are ready to roll. This book often has multiple choices or combinations of choices for answers, and that makes it tough to get ALL the right answers for a particular question. The quality of writing in this book is well worth the your effort, and not just for passing the test. I especially like all the comments in the book that are highlighted in blue rectangles. They are tips that are very useful but hard to come by in regular documentation.

The test itself seemed to be in between the level of CF_Buster and the BF Guide. These two practice methods will more than adequately prepare you for the exam, and do not require too much time to cover if you are already comfortable in Coldfusion.