The javaranch exam is definitely easier than the jweb+. I was getting 90%+ in it, while only getting 75%+ with jweb+.
That's not to say the javaranch one isn't any help... besides learning from the questions, it also helps get in that
test state of mind (it's not just knowing the answer on these tests, it's being able to read the questions correctly, and eliminate the wrong answers).