^I don't think it's the first try that counts the most. These review programs help you learn how to go about answering questions and at the same time, learn things that you might not have known about prior to the program. The important thing is to try to go deeper and understand the rationales instead of trying to memorize the answers to specific questions because obviously the chances of getting the exact same questions on your nclex exam would be very slim.
I'm no expert and I haven't received the official letter yet, but I firmly believe that nursing or not, that's how you make full use of your time (and money) on these review books and programs.