The ECS carpet has extra material in the front and the sides. This is to ensure that you have plenty of material to trim the carpet to fit the car. The heel pads are also placed in the correct place. The biggest advantage to the ECS carpet is that it is shipped flat. It is never rolled up and put in a small box. The carpet is supposed to be molded to the floorpan shape. When its rolled up, it looses some of the contour.
I havn't decided if it is worth the extra money for me. More than double the price is a little hard to justify. Now if they would bring their carpets to some major Mopar shows, I would definatly buy it from them.