I passed with 760 using exclusively Technologia.com for learning/training material (paid for by employer). I was getting above 90% consistently on the preptest, but after doing it several times, i mostly knew the questions by heart. Vary your material, if you can. Especially the practice tests. You don't want to simply know the questions by hearts, they are not gonna be the same as the actual exam.
The exam throws you off by asking you questions NOT in the material you need to know. Those questions are not worth any points, but you don't know which questions are worth how many points, if at all. For example, if you are about to use Tower of Hanoi, what is it you are about to do? (yeah i had that question)
They might also throw all the simulations at you right away. The first 5 questions i got were simulation, then i had none for the remaining questions. That was nerve-wracking as they tend to be longer than multiple choice questions, and you have a time limit on the exam. It doesn't feel good to be on the 5th question 20 minutes in. If your first questions are all simulations, don't let it stress you out, most questions will be multiple choices.
A lot of questions were situations. A lot of them seem to purposely have 2 answers that seem correct, but you can only pick one. It led me to believe the test may give you points if you choose a good answer but not as many as if you picked the best one. But don't quote me on that.
In the end, i wasn't sure if i passed until i got my score. Even though i was fairly confident going in, a lot of the questions seemed to be worded in a way to make you second guess yourself. I had just enough time to finish it, and but barely could review the questions i had flagged for review.
I remember going over all the ports and protocols before the exam, then getting a question such as: Which one of these protocols is used to retrieve emails from websites such as Gmail? I knew pop3 and imap retrieved emails, but i had no idea which one did so in this instance. And you can be sure both POP3 and IMAP were in the list of answers.
So i guess you could say a lot of questions caught me off guard, but not really materials or topics in general. Even though i was getting nervous, and at times even angry, i still passed with 85 points above passing mark.
Make sure you know your material enough that whenever they ask a black and white question such as "Which one of these is a fiber cable connector?" you don't second guess yourself on those. From my experience, there were easy questions if you knew the material well, but there was a also a lot of questions that had me second guessing myself, just by adding a twist (such as the pop3 vs imap question).
Know your cables. Know your connectors. Know your printers. Do NOT mess up on the work safety and professionalism questions; they are easy but still, i still got a lot of questions about that subject.