I agree with everything what Terry said, if you want pass with honor the SCWCD 1.4, the best existing book is the one of Kathy and Bert. Nevertheless in my case, as surely it will be yours, i could not wait for the book HF Servlet, becouse in my job they demanded to me to obtain the certification SCWCD 1.4 this week. Reason why, i was studying based in the Hanumant book.
I think that if you will study by the Hanumant book, you have to make an additional effort to prepare for the SCWCD 1.4, but as it says the proverb "If the mountain does not come to mahoma, then mahoma shall go to the mountain". But sincerely I think that the Hanumant book it help you in 70~80 % for the exam. And in this percent i assure to you that you will have to make exercises on a compliant J2ee conteiner like Tomcat 5.0 and will have to check in the specification if everything what Hanumant says is correct. For instance:
Filters it is a subject that SCWCD 1.4 check, but Hanumant dont talk about this, only because Hanumant think that it is important in the last chapter talk about this.
Another example, Hanumant dont mention anything about the attribute isELIgnore for the page directive of a JSP, because in the SCWCD 1.3 dont cover the Expresion Language
Another example, Hanumant explain that the container make a implicit mapping whit all servlet through the servlet path "/servlet" in a web application. In Servlet2.4 always have to make a explicit mapping.
And like that, exists another more few concepts. This weekend im try to make a document in order to summarize concepts that i found in Hanumant book that no longer they apply for the SCWCD 1.4.
In reference to the difficulty of the exams, I consider the SCJP the most difficult examn of all, due to the many tricks that can be obtained with the syntax and semantics of the language. The other certifications like SCWCD i think it is more memorization of an API and you have to probe that you know the rules associated whit these API's. Reason why, i think it is more easy, and it's better for people than they have good memory (not my case
). It is said that SCWCD 1.4 is more difficult than SCWCD 1.3, I believe that it is because they added these new concepts like Expresion Languages, Tag Files or JSTL, but the part of Servlet, WebApplication, Sessions, Security, JSP Pages, is almost the same. Reason why, most of questions that you obtain in Mocks Exams 1.3 it work for practice.
Greetings from Caracas...