my cert exam 70-228 is on the heels and I am utterly confused how to prepare for that exam.Will I do exhaustive study or stress more on simulation questions?
Your advice will be greatly appreciated.

If you are lucky, then prepare only on the parts that you go along with better - if you can't understand something from the first takes, then leave it be.

To be cautios and how it is normal, you should have as good as possible knowledge of everything, just to be sure that you will be good no matter the exam questions