Can't comment on 2013 model (so not that helpful really), but I recently got a 2012 125L - love this board - much wider than equivalent 2011 model in the tail.
Milsy, your right - more volume and width than 2011 - you've seen mine flying past you enough now to notice..

The thing keeps going once its up on the plane more than any board I have ridden, and it is FAST. Can only recommend them. Have sailed alongside the 2013, and as firiebob says - not much difference in the real world that I can notice anyway....