PG exams I felt are whole different ball game.
Strategy is key: Blindly spending insane amount of time on a single topic or subject is useless.
Objective: There may be biases in paper correction during MBBS with good writing, diagrams etc but MCQ exam cuts out all that.
Viva: This again needn't go well in most cases and the whole interview can be superficial.
Time crunch: Prep time and exam time are very limited hence planning goes a long way in PG exam.
Number of subjects: Few may do great at couple of subjects but PG exam needs you to be reasonably good at 19 different subjects.
Small subjects: Under rated during MBBS days, these are goldmine during NEET, although most of us have no clue what they are till PG prep time.
Practical / Clinical Knowledge: You can still pass MBBS exams with below par clinical knowledge, however NEET/AIIMS needs you to have reasonable if not great clinical exposure.
Kesha Megharaj, former Rank 12 AP-PG (2014)