dave...... said...My girlfriend likes both length and width...

Hmmm ... that would explain why she plays around so much .....

Seriously though: There is a rule of thumb touted by many of the board makers that 1cm increase in width is equavlent to 5cm increase in length.
A pretty broad generalisation Im guessing but it explains the trend to shorter wider boards lately - esp in the freeride category.
IMO manufacturers should include surface area along with length and width.
At around 75kgs - and with lots of boards to play around with - I am finding current model boards around 132x42 (give or take a bit) are way better than my earlier preference for boards which was always around the 137/138x39/40 mark. If these are roughly equivalent surface areas (the area I find suits me) then its
way better to be riding the shorter fatter board.
I guess that makes King Rowdy right again (but hey when is he ever wrong

)