Before I start, just a little FYI. I had taken a few accounting and finance courses before the exams, so I may have better background than somebody else.  I passed all 3 level on the first attempt.

Level 1: I did not use the notes at all, tried to read official books, but gave up since those books are not well wriiten and at a level for a typical US highschool kids.  However, I did as many practice exams as I can and most importantly, learned from the mistakes I made.  Results: handed in my exam papers a hour early for both sessions and PASSED.  conculsion: nothing hard and tricky, but just a lot of subjucts need to be covered. And the schweser practice exams helped a lot.

Level 2:  did not use the notes at all, tried and finished reading official books. i have to say this set of books are most useful in all 3 levels.  Also did all 6 sets of practice exams from Schweser.  Results: passed and managed to got off an hour early again. conculsion: the only level I learned something useful and it is hard.

Level 3:  finished reading official books.  These books are short, but similar to level 1 books, trying to explain every detail to you as if you are an idiot even though you have passed two levels. The concepts and focus of level 3 are heavily geared toward assets management. Also did all 6 sets of practice exams from Schweser and the official mock exams. Results: barely put down the last word in the morning written session and the afternoon session was relatively easy, manged to beat that last 30 min mark to leave ahead of the crowd.  conculsion:it is not as easy as people think, not much calculation or memorization of formulas. it is more about understanding of concepts.