I took the 90.1 with me, didn't use it. There were some questions that were you either know, you have the reference and can find it, or you take a guess.
My recommendation - if you have it readily available and your state doesn't limit references, take it with, but focus your efforts in these last days on doing additional practice problems and ensuring that you are familiar with your key references (MERM/etc.). Don't spend extra time trying to track one down...this isn't what will make or break your passing - it's the problem solving and practice that will.
Good luck!