I was the first to be surprised when I saw my result : 100%
I have two years professional experience and I've been building web apps for something like 60/70% of my time. Let's say I already knew half of the material beforehand. (using frameworks like struts or jsf takes you away from jsp/servlet base stuff)
Study material was HFJS and Manning's Exam study kit + Whizlabs. I'd say HFJS was my first reference as to what to learn and Manning essentially provided me with some extra on custom tag libs and design patterns.
Whizlabs is great though I found an average 10% mistakes in their questions/answers which is frustrating... I mailed them and got an answer in the vein of "forwarded your remarks to the technical guys, it will take some time before we can analyze your comments". I scored consistently 80% on their mock exams. IMO, mock exams like whizlabs is a must have if you want 100% security about passing or not. For this exam, they provide 4 full exams and 150 questions in topic scoped drill tests. For the drill tests, I set the time 30'. Default is 5' which is really short !
As a last remark, I had Servlet/JSP/JSTL pdf specs open all the time and I peeked into it whenever I wanted clarification on a subject I had just read/ a question I had failed.
Also when you see you have trouble with something, be sure you write a small web app just for practicing on that topic. Once you did that, you won't forget that easily. On the way you always push a little further.
Finally I spent about 3 weeks full time for studying.
My general impression during the exam was there are lots of really easy questions and then suddenly there comes a though one. Although I scored that well, at the end of the exam I was feeling like I could have at worst 85 and at best 95...
I hope this gives you a feel about what this exam is like.
AND BEFORE I FORGET: KUDOS FOR THE JAVA RANCH FORUMS, THEIR MODERATORS AND THEIR USERS!!!