If we're talking about the same confuser (the one with the photo of two rather 'spaced out' looking guys in a 727 just about to have a head-on with another a/c) - then it contains the exact same questions as the exam. Not past-paper questions in the normal sense but the actual questions you will get in the exam. If the exam seems more difficult it must be the stress/pressure of the situation? Or is your book out of date?
For what it's worth I am also studying the tech stuff as we speak (or was 5 minutes ago - glad of a break). I agree - there's a lot of it and I don't quite think I'm ready yet. Just answered all 149 and got 82%. Need to read up more on the first ones on the atmosphere - wasn't expecting those. I also have trouble getting my head round the Met. stuff - glad it's not just me.
Wasn't trying to imply you weren't studing properly, by the way - I did acknowledge that you said 'for revision'. Just making a point for anyone else who is in the same boat. Good luck.