Which wire are you talking about? The thick one at the back? That lets you set the highback angle.
As for why to get them... I have traditional 2-strap bindings and flow bindings. The flows are harder to set up properly the first time, but after that it is lock-and load each time. Unlike 2-strap bindings, you don't have to fiddle with them each time you get off the lift to make sure it isn't set too tight or something.
Flows can be tricky to get out of when you're dead tired and don't feel like bending over. I like mine. They hold my boots.
i hear alot of good things about flows and i want to know what is with the wire on them..and wht would be a good bindings for freestyle riding.