I'm using the 121 carbon version in the second year now and my ~80kg are feeling quite good on it. Mostly with 8,6 or 7.5 in the open sea or choppy conditions. Up to now the board is keeping strong and no signs of weak spots so far. The only weak thing I found is the ultimate light wind performance and this is the reason why I ordered a 127 from 2012. It might be not as handy like the 121 but next year I do want to win some races and my weight is above the average here in Japan and almost all pro's are on the 127 even thoguht that they are below 70Kg some times...
The 2011 version has often problems with the plug-ins for the straps which break out after some serious usage. The rest of the board however is just excellent and doesn't break or get soft within one season, at least what I can see from the local Starboard pro-riders.
Hopefully Starboard worked on this for the 2012 generation.