I started a similar thread on another forum several years ago.
The large majority consensus was that the 'gangsta' grip was a more natural hold than the popular verticle one.
Just hold your hand out in front of you, it will be sideways.
How well you can shoot that way is another matter altogether.
Maybe guns should be designed for the sideways hold. I dunno. Just tossing the idea out.
FWIW, I have never tried shooting with the sideways hold and have no plans to. Habit and conditioning bring mine verticle without thinking about it.