I used both HF 2nd editon and SCWCD exam study kit (Manning publishing), after studying HF for the first time. Both complement each other in my opinion. Manning's book is a bit more organized (and formal) and I liked better the sections on filters and tag files.
Well, I was disappointed in general with some of the questions, about 8 or so, where all about having that specific thing in your head, which by now I probably wouldn't know the answer. The test asking for intricacies of tags is OK in my opinion, since it's the kind of stuff which is very often put to use, but some things just the kind of stuff you'd be googling for the answer.
The most "real-life use" questions where about packaging rules and design patterns. I don't know if it was my impression, but I felt like there was a lot more scriplet code than EL and as usual there was the kind of stuff you'll never use.