The Z mouse will bring you to another dimension, mannnn. But not actually. What it’ll do is let you use your mouse in unconventional ways. Like:

You can tilt it to different angles to control when you crouch or lean during a game without having to hold down a key.
Or:

You can pivot the mouse so you can run forward while also turning to the side.
And finally:

You can use it "in the air" because why do you need to keep a mouse on the ground, right? This function apparently gives you better control when pitching, rolling, and yawing. It seems like a good wrist workout to me.
The Z also has 50 buttons arranged around its body and supports Deep Click, which lets you use pressure to tailor your clicks to what you're doing. Noted and appreciated! The Z is on Kickstarter now and starts at $139.