I found the exam to be a little challenging, but passed it no problem the first time, with time to spare at the end. If you can determine the level in your head using the 1995 DGs, you will pass. On some of the examples I didn't even need to use the audit tool. The thing here is to practice determing levels over and over to obtain both speed and accuracy. If you already do this at your job day in and day out, you will be fine. The thing I found to be most challenging was that it was very repetitive, and I was tired at the end of the 3rd hour. My mind started to wander and I had to take a break.
I purchased the AAPC practicum and found it to be very similar to the exam and I highly recommend it. I also purchased The Evaluation & Management Step, An Auditing Tool by Carol J. Buck, read and did the examples, and found it also to be helpful. There is also a three part tutorial on the MedLearn website.
I think if you take the time to prepare and practice a lot, you will be just fine. Best of luck!