For some reason most of the IMGs I know that have taken Kaplan prep courses for USMLE step 1 have failed the test or barely passed.
I stayed away for that particular reason. Though I do highly recommend Q Bank. However, I used it as a supplementary resource and I also used it to gauge the progress of my studies.
I have been an average sort of a student, never too bright, therefore if I passed step 1 (rather comfortably), I am sure you will be able to do so as well.
I used the following study materials:
BRS for path and phys
Ridiculously Simple for micro + First Aid
High Yield for behavioral science, neuroanatomy, cell and molecular biology, immunology
First Aid for pharmacology, anatomy, biochemistry
One common mistake that I feel many of us make is not memorizing the material. Just reading and re-reading through the above books would not have been enough for me personally. Although, I did not memorize every topic of each book listed above, I did more than a fair share of rote memorization for Step 1.
Good luck.