If I wanted to create a square with a hole in the centre, would it be more efficient to draw the square on an Alpha’d texture and stick it to a square face, or to create a square shape with a hole cut in it and apply the visible square part of the texture?
It depends on a few variables, but I’d say in general the transparent texture would be better, as long as the texture isn’t too big.
Note the -in general-. You’re best to try both and see what works best.