Wings on the inside of your binding are going to give you more edge to edge response. The wings on the inside of your calves will give you leverage in the center of your stance for when your carving front to back. Wings on the outside will give you leverage on the outside of your calves so you can push up on them for when you tweaking tricks and getting wiggly.
The Flux DMCC light and DS30 have the asymetrical highback so you can switch them for a different feeling ride. Its not going to be as stiff and responsive as a full wing, but you will get a switch in leverage when you switch the left highback with the right highback.
The DMCC light is going to be a little stiffer and lighter weight than the DS30. Both the DS30 and DMCC light have the same highback and baseplate, but the DMCC light is carbon infused, and the DS30 is made from a mid-flex fiber glass. The DMCC light uses titanium hardware for lightweight and the DS30 uses tooless screws. If you care about lightweight, get the DMCClight. If you want to save some money, do the DS30... it will be almost the same feel.
I will say one thing for Switchback.... the tool-less is cool.... but Flux has been doing that for years.