A pedal is basically a recoil catapult and like a catapult, there are many factors that contribute to the smoothness or speed that the object( beater ) is propelled with. So, a Ghost, or a Gretsch Floating Action or any other pedal has an action that is determined by a lot of mechanics. The spring recoil is only one of them and Ludwig didn't invent magic springs. Any differences you sense between those three pedals is the result primarily of the mechanics of leverage, rotational force and friction, pedal angle,pedal mass----a whole bunch of stuff.. It would be possible to convert the shaft ends of a speed king to an extension spring design, leaving all else the same and feel no difference whatsoever. It would all depend on the temper and relative stiffness of the springs employed and the freedom of the extension..
Wow! When did the forum get all sciencey and stuff? LoLoLoLo