Well, I didn´t use any simulators, I just took an course for fundamentals and then I read the Certification book from McGraw Hill, but I guess if your friend told you that, you should buy/use it, what I do suggest to you is that DO NOT take the exam if you dont get 80 or more in your tests exams, otherwise you'll get a poor score.
Kind Regards,
_____________________
Ing. Gabriel Gutiérrez
How good are certmagic.com practice exams for JAVA exam? My friends
told me they are pretty good and he has passed many exams with their
material. Let me know guys!