I've had the 11 4 Nalu GTW ....great board. Quite thinned out in the nose and tail and actually has heaps of rocker. I used to surf it in small stuff and slightly overhead waves....nothing steep though. It is very much a surf shape rather than anything else but it is long enough to flat water it...but it isn't fast
Has a great rounded pintail and with a big new single fin it was glide heaven on big rolling waves. It caught stuff super early....further out than anything else I have surfed...but it was my biggest surfing board by a mile for sure. Way too big for your weight though...you will find it hard to turn off the tail.......find a 10 6 Nalu and you are laughing.
I am 90 kg and used it for surfing and a few coastal paddles....only short ones. I sold it on as it was just too easy....I partly regret that now but 11,4 was just too big for my surfing.
The Nalu 11,4 and 10 6 are great boards...user friendly and work.
The 11 x 31 looks tubby to me ...not really refined in nose and tail....but I ain't seen one in the flesh.