I have ridden both and I like the Scorpion more,both were good for different reasons. The Scorpion was like a small longboard,in the sense you can(well i sorta did shuffle my)get to the nose. I like the fact you can surf the tak as multiple fin configurations. I like it as a quad.
The sumo.was a bit more forgiving with a late take off with the flipped nose. Yet the tak will get you in a wave way earlier so the tak wins again.
In saying all that,I always was keen to Buy both boards.....now I would not buy either. I would buy a egg shape over the both of them for small wave fu n and for how you surf them....as in a small longboard or buttons type fun machine.
On the argument that they will go good in bigger surf,well maybe,but there are far more shapes in bigger surf I would rather then those two.
Out off the two I would buy the tak...after my brief love affair was over....I think they are a gimmick shape