The post - believing in the post, as in redirecting pressure, is a total complete and utter fail. That's not how fluids work. At all. Not even close to reality. Any difference seen is experimental error.
The rubber filled cavity - again, not how this works. Not even close. In fact, vector analysis of the forces at play will show you it doesn't help, it hurts.
Hollow points work based on the shape (how tolerant it will be to being plugged), lead hardness, jacket hardness/thickness/scoring. Plugs, posts, and whatever.....that's the fingerprint of marketing.
The Hydrashok was marketing genius. So was the Black Talon.