bmg,
I think you are already well prepared . You'll be fine.
My opinion is to finish kaplan Qbank first ( 600 quetions left ) in a week or ten days ( by the way, how long are you planning to do them ?), then to take the NBME self assessment tests in two consecutive days and finally to start your final review.
NBME are the best existent self assessment tests on the market: two forms of 200 questions each ( four hours each test ), that are written by the same authors who make the real exam; that's why these tests are said to resemble the real exam. Each test costs $45 and can be purchased using the NBME website:"
www.NBME.org, after you open a personal account on that web site. You can take the tests either in standard mode ( time mode ) which I recommend you to do : both tests in two consecutive days or they can be taken in self-paced mode which means untimed tests: four hours for each block of 50 questions, so a total amount of 16 hours per test.
At the end of a test you will get a profile similar to that you get when you receive the result of the real exam and a score and moreover the correlation with the real exam. Of course, it's just an estimation, a prediction, there is no guarantee that it will happen exactly the same on your real exam.However, these two tests, their results are considered to be the best assessment, to have the best correlation with the real exam as well as to resemble it.
Good luck on your preparation and your exam.
matoka