I haven't skied a lot of deep-snow skis, but I have skied the old Ripstick 96 in 180 cm, and I am very familiar with Ontario and Quebec snow.
From what I recall of the 180 RS96, it seems to me to be the perfect balance between an on-piste ski and a deep-snow soft snow tree ski, but to me that's not a good thing.
It is like an all season tire. There are so many better true winter tires, and so many true high performance summer or at least pavement-biased tires, and having driven many of them, I could never be satisfied with the all-season compromise. I have race skis and carving skis that are 68 mm at the waist in a wide range of radii, and coming soon, a 108 mm wide full rockered ski for soft snow (finally). Obviously I think you would be better off with a quiver of at least two skis, one wide with full rocker and 19 or greater radius, and one narrow with camber, but to each his/her own.
Folks have complained that the RS 96 is not comfy at high speeds. It's true, it won't have the composure at a mile a minute that a speed ski has, but it can handle the speed well enough that its stability (or lack there-of) wouldn't stop me from enjoying it at those speeds; it would just feel very fast, and not make 50 mph feel like the ski was just waking up.
Knowing what I know about eastern Quebec snow conditions, I think the Black Edition would move the set point closer to the hard snow end of the spectrum, at the expense of the soft snow suitability. Given that you have already compromised the soft snow ability so much already, by not having a true soft snow ski, what's a little bit more? It (the black edition) would probably be a better bet for the all-season ski given the seasons where you ski.