There was a thread regarding this recently:
https://g05.bimmerpost.com/forums/sh....php?t=1666347
It all boils down to personal preference and what you're wanting to do with it as TurtleBoy stated. The air suspension is a much more comfortable and smoother ride, but if you're looking for something very sporty and stays flat in the curves, it's not the suspension for you.
I personally got the air suspension because for me, SUV's are more about comfort.
The best way to tell would be to just get out and take a test drive of both suspensions.