I have read alot of the posts about this method, with the keeping intact of the vertabrae and have come to the following conlusions. I used to be a die hard head wacker, quick and easy for me, also thought to be the fastest way for the animal, I have slaughtered hundreds of my own backyard free rangers. Without knowing exactly how it feels i would like to say that i once had an accident with my leg where i cut the main artery and was bleeding severly, may be due to shock or adrenaline but i recollect that i didn't feel any pain and I also have broken my arm and this did damage to the nerves, ( wasn't a clean severing like as would be to a chicken) but it hurt a whole a hell of alot. This makes me lean toward that although it is a bit more timely and "looks worse" it may be true that it is less painful for the animal, but those who say "How can we know? if we haven't experienced it?" are right, and we may never know, this is just my opinion based on my personal animal slaughtering experience and my near self slaughtering follies. I have found however, that the meat is softer with this method, probably because there is no "stiffening shot" of adrenaline sent to the heart and muscles when the spinal cord is "whacked". I like to eat softer meat. Also something very interesting i learned in another country is an asfixiation method. You sit calmly with your future meal on your lap talking to it, calming it down, caressing it, for about 10 - 15 minutes and ever so slightly throughout the process you press down on their throat "wind pipe" and they just sort of fall asleep, this actually works and there is no sudden stress or freaking out, they just turn off and they meat comes out really soft, try it and give me your feedback. No hate comments please, just my opinion in an attempt to help others achieve their goals, it may be that you have different goals, and i respect that, thanks.