I have the orion and love it for the park and it is ok on the mtn, I also have a Marhar throwback 156 and it is awesome for park and all mtn. I think it is more cause the throwback is a 156 and I ride more out of the park then I do in it. The best part of the orion is the 3d edges so it is a lot harder for me to hit an edge when board sliding. I also am just about your size also so a 156 for park will be fine if you want it to go elsewhere also.
How is the throwback in powder? I was thinking of picking up that or an archaic as an all mountain freeride board.