That was a nice surprise for a late Thursday work day.
I'm cool with 4th Gear. Better than 3rd Gear. Logistics sort of work, he's big, strong, haki-hardened but also totally elastic rubber. Ok, so he can absorb in attacks and knock them back out and can trigger shoot punches/kicks and movements like Bellamy spring movement. That makes sense as a rubberband is spring-like in movement when you snap it and I like that it gives Luffy some teleportation style speed + better defense + more impact attacks.
What I
don't like and is hard for me to accept even in magic book physics comic world is how he can change directions in the air (hmm, actually I can buy this if while flying in a direction he snaps part of himself quickly to change direction and shoot elsewhere) but the last attack with the mid-air direction changing fist...yeah, no. That makes no sense in any way possible and it annoys me

Like all the rest is cool, but why give him a dumb totally bs attack like that? The best explanation I can give is that he aims at a specific point, like Do's face, and shoots it off with such force that like when you try to pump something with pressure and let go it just snakes around like wild on its way in that direction from the internal pressure.
HMmmm
Also dunno why they translated it as Bound Man when even the line in the notations say it's supposed to be Bounce Man because he's a Bouncey man.