Passed it !. Total study duration : 2.5 weeks.
I would suggest people planning it to go for a 2 month duration of study - rather than just a week or two !
Reason being - hands on requires a lot of time - especially with NIO2 and Concurrency classes. And then - it's better to give with more hands on than less !
The first thing to remember for this exam is read the API Docs - there is so much more information in them than any of the books - You will be surprised that they are very elaborate for a lot of things.
So read - every method definition,even each constant definition, exception - hierarchy - when and how it is raised. Go through all of it.
As of now , no book covers details as much as the API DOCs ;) So read them before you give the exam.