I try my 81 this week end too. Very good planning like acid/kode, good upwind ( easy and good upwind angle). Just find the top end speed of the board is limited (of course with 4 fins...) and the appel of jump is less easy that on a twin or single fin.
In surf quad looks like give a lot of grip and is more directional than evil.
I wait better conditions for test more in surf.