Hi Martin, you may be missing a key element of the discussion / response here; one of the main improvements in the 2013 board over the 2012/2011 is the way it runs more freely (over chop) with less impact under the mast foot area. This contributes to better top speed potential and a less tiring, less physical impact ride for the rider.
These are attributes (improved trim at speed) one normally associated with variations in rocker (!!).
In fact, the biggest gains in 2011>13 have been the result of pinching in the very back tail outline (2012 update over 2011) and new tail cutouts (2013 over 2012 and 2011), all of which allow the trim of the board to improve and run more freely, delivering high/er top end speed and more comfort/control than previous while still retaining the "maximum efficency" iSonics have become renowned for. There is a lot more going on here than simple "rocker" or bottom shape variance.
Rocker normally refers to the centreline template (often - as in this case- itself does not tell the story)..
As usual, doesn't sound like much in theory (and it does not represent a significant mm variance in rocker);
one can argue "no real difference, what's to bother about..." but for those who have tried it, the result/s are quite clear.
Not sure if this resolves the background to your question....or not ? A quick ride on both boards will.
Cheers ~ Ian
Last edited by Ian Fox; 15th January 2013 at 09:39 AM.
Reason: Spelling typo....