Repling to a couple things here...
1) the ski is not wider throughout, it's wider in the tip and wider in the waist, it has the same tail width...
2) what does the new shape do? It lets the skis float better and make more different shaped turns. the skis are more versitile and you don't have to lean back as far when skiing powder, the tips float more so you don't have to worry about stuffing the tips in the snow.
3) also, as far as I know, the base material is exactly the same, but since it's not super die cut now it's faster. When the die cuts get chewed up they snagged the snow a lot and casued a lot of resitance...the new bases are faster and k2 made them without the die cuts becuase Pep, Seth and the rest of the pro's requested that...