I didn't have too much trouble with the Practice of Geology - as an environmental geologist, I had all of the hydrogeology down cold. I'd also gone a little overboard on the oil and gas calculations when I was studying, since those were new to me. So even though I didn't have any professional experience with those topics, I was ok with those questions.
I was able to work out some of the obscure vocabulary questions by process of elimination. And I could get through some of the longer form questions (like the ones that referred to a geologic map and asked "which event happened first") also by process of elimination. The parts that tripped me up tended to be the areas of geology that I had some familiarity with through work (like engineering geology and geophysics) but that I don't actually do myself. When I came to specific questions in those topics, it turned out that my vague and minimal studying wasn't quite enough to answer them.
I ended up taking my PG tests with several people I knew personally or by association, and most of them failed the Fundamentals of Geology test. I wasn't comfortable asking them what parts they particularly struggled with, especially considering that I ended up doing ok. So I figured I'd put it to the general readership: if you took either test, how did you do with the material? Did you discover any unexpected gaps in your