I personally haven't used it but there was a friend of mine she had this review and she really liked it..And there are good reviews about this review on here too..check out some of the threads from past
I'm using NCLEX RN 10,000 and currently at mastery level 7.3. The questions are tough, thought-provoking and quite similar to NCLEX RN exam. Each time I read the questions at this mastery level, I have this "huh??" look on my face. It's quite intense. I've encountered several meds, disease processes, etc that I've never heard of. Definitely much higher level questions once you've increased your mastery level.
I need all the help I can get that's why I've invested in various NCLEX RN resources and the fact that I graduated BSN eons ago.