I've skied on them before but I have a friend who really likes his pair.
However these will not be good powder skis because they're fully cambered (rocker is better for powder) and they have narrow tips, tails and waist.
If you want to ski powder and ski park look at something like Armada Al Dente or Nordica Soul Riders both are wider skis and have rocker to help in powder.
i found some pow last season and let's just say it didn't go the way i wanted it to...
if you're looking for a park ski that will handle a little better in pow, look at the Volkl Kink...same construction as the Wall but a little wider underfoot and rockered at the tip and tail.
If you like the Wall, maybe consider the bridge, a wider ski but is still built with the same materials as the wall so will have similar stiffness ect.