How realistic are the questions on the Practice exams in books?

ericsp1

I have been studying the practice exams in both Meyers book and Prowse's book. It seems as if you are walked through the Meyers questions. On the other hand the Prowse questions are more challenging.

Which book practice exams or other practice exams offer the most realistic questions?

I also own the Testout software and there are major differences in question wording.

Basically I'm looking to gauge my knowledge so far and would like to be able to restudy the areas I'm week in. I guess this is where the Practice exams come into play.