I'm not a team member but I see for some reason lately that queries regarding wave boards are not getting any/many responses. I have also sent a post and got no reply yet. Hope the wave guys are all ok and in one piece ha ha.
Anyway I can't answer what the difference is between the 2012 and 2011 as I haven't seen the 2012 board but looking at the statistics the 2011 is wider at the tail which personally I prefer as I only have one wave board. I have the Evo 2011 71 carbon board and I weigh 68-70 kgs. I have only used this board with a 4.7 and 4.2 sail and to be perfectly honest with you I haven't managed to get out much on this board so far. But having said that it all depends on what sail size you are looking to use and in what conditions. The 76 board is quite wide (57.5cm) as opposed to (56 on the 71) so in overpowered conditions you might get bounced around a lot. So if you are looking to use the board on 5.5-4.7 then you might opt to go for the 76 otherwise I personally recommend the 71 hands down if you are going to use it for 5.0 and less.
p.s (I'm also waiting for a reply on 5.3 and 71 which might help you out as well.)