Well I still slightly disagree. I still say a 151-159 will take you places a 144" just won't make it, in the right conditions of course.
As far as the long tracks being a marketing scheme...i say they are here to stay and will only get slightly longer. Reason is they really don't make that much of a difference with a tipped rail you can't even hardly tell on harder snow. I rode our '04 700/144 Vertical Escape early this year for a few trips and moved to my 800/159" Vertical Escape later this year when I bought it. I couldnt tell a difference at all, besides the extra climbing power from the bigger motor and longer track.