I agree with Chesapeake. I am fairly heavy at 85-90kg so have the Quad 81, have had it six months. Its a fantastic product from Starboard taken the Evo concept forward.
BUT I did not really like it for the first five or so sessions, it felt weird and a bit draggy in a straight line (and loves to point upwind!). Another sailor on the beach bought the 86 Quad and traded it after the first session (wealthy guy...!!).
I also found the outer fins were loose after the second session (very very loose). Tightened them - so much better, then they loosened again. I ended up putting some sailcloth in to tighten the box fitting and have never touched them since.
Its a fantastic board but as in any experimental design it is going to need to be tested over time not over one test session.
I can not recommend it highly enough for any dedicated amateur wave sailors, just stick with it, make some adjustments, and you will be rewarded.