I am new to One Piece.At first I was confused about Luffy using the Gear abilities, then someone told me that it was something new Luffy developed on his own, not other Devil Fruit users can go Gear mode. I think he told me that Luffy puts air into his bones and muscles or something and he was inspired to use it by the Sea Train, I'm not sure about his exact words. Luffy's Gears is his own way of putting his Gear powers to the next level.
My question is can other Devil Fruit users also put their abilities to the next level? In one episode I saw Chopper eat some giant pill so that he could use some hidden abilities. Did Chopper get his powers to the next level? In a later episode I saw Chopper In a beast state, he lost control and he grew bigger. He did not eat a giant pill, but he went insane.
My conclusion is can other Devil Fruit users also put their abilities to the next level like Luffy(It doesn't need to be called "Gear") and the thing about Chopper.
Wow, I really typed all this down for a anime, I am surprised at myself.