I took the Java Architect exam for Part 1, and I passed with the score of 89%. Here is the breakdown:
Common Architectures 83%
Legacy Architectures 100%
EJB Container Model 100%
Applicability of J2EE 100%
Design Patterns 100%
I found the exam to be extremely wordy, and not too many code examples. The verbose questions are usually the architecture ones. The best way to handle those is to draw a picture and jot down the key words (such as Corba, secure, https, mainframe). It organizes the info logically; so, it will help you in determining the answer.
I had only 2 questions on applet security. I studied security intensely, but could not answer one of them.
I think the main design patterns on the test were iterator, observer, state, proxy, factory, and adaptor.
For UML, make sure you know what is composition vs aggregation, generalization and realization. Also, if you see a UML diagram that you can express the diagram in a sentence.
Of course, the most important are EJB's. But it is not that difficult.
How I prepared
To gain knowledge in EJB's, I read the "Mastering EJB's" by Ed Roman. It is a very good book. O'Reilly's "Enterprise JAvaBeans" by Monson-Hafael is just as good.
Once I was done reading the book, I went through John W's notes (John's notes is at http://www.javaranch.com/scealinks.jsp).
Basically, I took a few weeks time reading the notes over and over again until I literally memorized it.
Then, I took the mock exams. I thought Ian Anderson's and Sanjay's exam were the best. (I cannot find the Ian's link right now. Sanjay's link is at http://groups.yahoo.com/scea_prep).
They really drilled the fundamentals. Make sure you go over the exams several times till you are perfectly clear. Ian's exam is very similiar to the straight forward portion of the real exam. But once you have mastered the fundamentals, you should not have any problems