I did all of the CI tests, none of the others you mention there. I would say that the test was more difficult than the CI tests.
It's not so much the material, but the way that questions are asked. The NCEES test has a way of asking questions in a manner that is meant to confuse you. Sometimes non-pertinent information is provided, sometimes there is a word in the sentence that makes the problem a lot more work, or a lot less. There was one question in particular on the test that made me re-read it over and over to be sure of my answer. Of course, after discussion with some work folks the next day on my method (cause I couldn't remember the exact question), turns out I was probably wrong, which is tremendously frustrating since it should have been a gimmie question on an easy topic. I always found that if I did my calculations on the CI test and my answer was one of the choices, I was always correct. I also felt this way about the FE which I took in October. For the NCEES test I had several occasions where my answer was one of the choices, and it was wrong.
Overall the CI tests do a good job of making sure you have the fundamentals. There were no tricks, but I felt they covered all of the important aspects of the tests. However, when I stat down and treated the NCEES practice exam like the real test (spent a Saturday at work with no distractions doing both 4 hour sessions with a 1 hour break in between to simulate the exact test environment/duration) I didn't do nearly as well as what I did on the CI tests.
On the CI tests I would break them out into 20 question sections and give myself 2 hours. I would then use my strategy where I read all questions and give them a 1-3 based on difficulty/time to complete, then do them in difficulty order. By the end of my studying I would routinely get 16-19 correct in each block of 20.
The NCEES practice exam shook my confidence quite a bit, and sadly there is only 1 of them.
