My answer on Quora:
I have done both thus I can help you understand.
Although the topics covered by all entrance exams are the same however each one is very unique in its own ways.And to excel in any particular one you need to master its specific pattern!
1.USMLE tries questioning your basic concepts in a very different way that has never been questioned while studying for MBBS. So one word you can say : USMLE= CONCEPTS APPLICATION
2. Indian MD/MS exams the pattern of every exam be it …ALL India/PGI/JIPMER/NIMHANS/AIIMS the pattern and portion of topics although the same , difference lies in repeat topics and stress on some particular things. MCQ level is also different in different exams like PGI is multiple right answer based, AIIMS although single choice of correct answer covers more topics on recent developments and research.
I hope you are understanding what I am trying to convey…that its not possible to get good scores by studying for multiple exams as the same time even it the topics/portion of subjects are same. They require vigorous preparation in their specific pattern for long time uni-focus to excel.
From your query it seems you are still in the deciding phase to select between the two different country exams.
Don’t let anyone discourage in your pursuit by telling something is difficult. The most difficult part is starting to do something which most people don’t do.
Everything is achievable and within your mind’s limit.
Good luck 🙂