User blog comment:ChiroSamai94/One things that's been bothering me.../@comment-1595565-20110717173925

It looks like Luffy activated Gear 2 so he would have better leverage for the attack. He attacked the Pacifista by driving its head into the ground. That would be pretty hard for anyone of his strength to do. I'm not saying he needed Gear 2, it was just the quickest and most effective method for the job. The same with Sanji, the attack looksl like it provided better leverage. It's an interesting observation, but not the best way to judge. It would have been better if they had all taken down a Pacifista from the same spot (in this case, the waist would be the best way to tell).