today I cleared OCE JWS with 87% and I'd like to share my experience.
Two months ago I've made a bet with my friend that we'll clear it in two months, so that was my preparation time (although not even close everyday study).
I followed the exam guide from JavaRanch - two books - WebServices Up and Running, Ivan Kriszan Study Guide in this order. If you can take very detailed guide from start you can begin with Ivan's book.
I was practicing using enthuware - everytime I didn't know the answer I studied that topic again. I didn't go through all test and when it comes to complete tests I did only test 1 and last day test (yesterday) with 96%.
First 15 questions didn't seem very familiar and I thought WHAT THE HELL?! But soon began the questions that resemble enthuware.
There was one question that surprised me very much. Something like "MTOM allows to save X percent of traffic in comparison with XML". I didn't know that MTOM saves anything :-)
P.S.: This was my last missing java exam, so now I have them all (but most of them from good old Sun) :-D
as I have experience with all Java certs I think that JWS is the hardest - lots of XML based specs. And without any exaggeration I think that I would not be able to do it without Enthuware. Keep working on it ;-)