Hi,
I failed big time in K&b and inquisition about a month before I took the exam.... And I remb scoring less than 60% in both... Then took about enthuware tests some 5 of them, about a week before the exam and it was about 70 -80% ...
The actual exam was a lot easier and I made 87%
Tips:
Both K&B and inquisition (i donno about Devaka) are pretty tough and such exams you can use primarily to develop a good eye for the 'traps'.
Enthuware exams cover ground. Those exams can be used to assess yourself and revise the whole syllabus.
And after each test that you take up, spend time researching thro the docs, on the questions you got wrong.
Also try short programs on places where you went wrong.
I got a 100% in Generics, multithreading and IO and those were the chapters I remb, I had read and done a lot of questions on. So more you work on a chapter, the more you are gonna get.
For generics, I so much liked the pdfs from javabeat.net Those are tough and a little beyond the syllabus but I guess that is required to make you feel confident and at ease in the actual exam.
Regards,
Vishwa