I took AUD today. Chances are, you'll end up with a lot of time left over if you are a pretty quick exam taker. I ended up finishing all of 90 of the MCQs with 3 hours and 25 minutes left in the exam. Probably spent about 1 hour and 15 minutes on each of the simulations, primarily on the written communications (double checking grammar, sentence cohesion and structure, etc.).
Nothing was a surprise, except for maybe one or two MCQs and a small portion of one of the simulations (which, in my opinion, were probably pretest questions due to their inherent ambiguity). I use Bisk's online course because my firm (KPMG) pays for it directly. I probably saw anywhere between five to seven MCQs that were exactly the same as those included in Bisk's material.
Overall I would saw the more salient things I encountered were SSARS and SSAE questions on the MCQs, and a deep understanding of internal control and substantive testing on the simulations.
Finally I'll add one last comment: because of the careful wording of AUD questions and subjective judgment between two answers, I'd take the day off before the exam. This means no work and no studying, if possible. Cramming that last day probably isn't going to help, but being fresh and relaxed for the exam is.