Just a skeptic talking here, but i wouldnt want the stiffness of the driver x for my softboot setup, i figure thats what the hardboots are for right? On that note, ive heard great things about the burton ion, and id probably be looking at those first if i ever need a new pair of softboots.
edit: i feel like i havnt given it credit in a while, so i'll throw out one more suggestion: if you want something more directional, Pogo makes an awesome freeride board (a very powder oriented carve board, you might call it?) "The Longboard". Can be ridden with hard or softboots, in case someday you change your mind and want the power. the Dupraz D1 is a simmilar shape, though even more powder specific than the Longboard. Both beautiful boards.