I disagree with Carmack on this, I'm on the other hill. The press-on-release affords me the chance to bail at the last minute. It's probably because my brain is defective, but then consider it a handicap aid! But something about the way I work, makes it that my last cognition will often happen as I'm holding down the button, and it's not uncommon for me to realize that "oh shit, this is the delete button, I meant to save!" and! With the do-on-release, I can keep holding down the mouse button and carefully move the cursor OUTSIDE the button, so that the action is not executed.

Lot's of places, I want faster response (the controls in computer games, yes, of course!) but NOT in interface elements, there I want the response on release, so I have the extra opportunity to realize my fuckup and amend the situation.