I have not personally seen the SST, but i have seen and toyed with the Zariel a bit.
I liked the concave and feel of the zariel, and the general shape of the whole board. I did not get to ride it on the water, but its one of those skates that you touch your feet too and go "this was meant for me". I did some carpet shuvs and big spins, and when its under your feet, it feels nice, and takes alot less to spin around than you would think a 13 pound board would. One of my friends rode it at radar lake, and said that the pop on this board was incredable, way more than any other skate he has ever been on (he sells LF and Ronix skates).
In talking to the Rep, i learned that the board is also practically indestructable. since reed hansen has started riding them, only one has been destroyed, but it wasnt from the water, apperantly, at the toe jam, a bunch of the riders made a fire out of their skates, and somebody threw in the zariel
The rep had no idea why that happened either haha.
so keep it out of fire, and the zariel will keep you happy.