Hazel,
Just as Mark did, I found the real exam to be more difficult than the simulator. However, the types of questions and format are very similar. I think the main difference is that the actual exam has answer choices that are more similar to each other, which will require more deductive reasoning.
As long as you take a little extra time to re-read the questions, you will see many times that it is simply the way the question is worded & that will help the answer become more clear. Bottom line is to relax and don't let the time limit cause you to hurry through. I'm sure you'll do great!!
Best of luck,
Allison