MLeake, good post.
I will add a few comments here for the sake of clarity.
A temporary cavity is not what I consider damage. I am not going to say it is of no value since I believe there is value in pain. How much is debatable and I certainly wouldn't put faith in it. Damage is obviously needed to cause incapacitation.
I agree that momentum is generally a better indicator of penetration in soft tissue. Hard barriers are a different issue. Again, it goes back to how much of the energy is used effectively.
I also don't disagree in regards to shootability, especially in regards to small easily concealed handguns. Every firearm is a compromise and that is certainly true of handguns. That is a different question though.
"Those who would give up essential liberty to purchase a little temporary safety, deserve neither liberty nor safety."
- Benjamin Franklin