No one right answer - how do you carry, what do you carry, how many different options do you need given circumstances? Each has its uses, it's pluses and drawbacks.
Let's see - I have multiple IWB holsters (Comp-tac minotaur, Allessi APX, Don Hume, etc.), most for AIWB. I have a smart carry (thunder-wear) for deep conceal, a Ultra-carry (kangaroo carry) for under the arm, an ankle holster for BUG, a shoulder-holster for when I need it, and belt pack holster, just in case. There are others, but the points seems to be made.
What is best for you in a given situation?
Most often I carry AIWB - may carry BUG in ankle holster. But will, when the situation requires it, go with other options. I remember reading when I first started carrying that most people end up with a drawer full of holsters. I wondered why.
I still do whenever I look at my drawer full of holsters ;<).