IMHO, both the anti-spin and the fold flat load floor are must-haves.
The load floor lives under the rear seats on a quad cab. If you fold the seats up, you can unfold the floor, giving you a flat surface to transport stuff inside the cab. It's split 40-60, just like the seats, so you don't have to use up the whole back seat area.
In addition to hauling, I sometimes unfold it and then put the seats back down. It gives the grandkids a raised floor instead of letting their feet dangle. A kid with dangling feet WILL kick the seat in front of them!
Bob