I'm curious about this.
First, my definition of crud is "Rocky Mountain Crud." To me, this is snow that fell as powder, but you are now skiing on it at 2-3:00 in the afternoon. It has been pushed and packed into piles of inconsistent firmness, has been sitting in the sun and getting wetter, and while generally soft, lacks any real consistency to how it will ski.
I've been skiing since the early-mid 80's, and in that time, I've found that just about any ski will be fun when skied in nice, light, untracked pow, with the main difference being how much the ski will float.
However, it seems crud (in my opinion) is what sets apart good powder oriented skis off from bad ones.
When I got my first dedicated powder ski a few years back, my experience in skiing crud turned around 180*. Before, when running hard snow and/or all mountain skis, when the fresh stuff got tracked out, I'd stick to the groomers for most of the afternoon, because when skiing crud, the skis would just get pushed around too much.
So, when I got my first set of dedicated powder skis (Atomic Sugar Daddies, 99 waist), suddenly it was a new world. They track cleanly through crud, they don't get pushed around, and they make skiing deep snow a joy from open to close.
Problem is, my Sugar Daddies are running out of tunable edge, so I need a new ski. Problem is, I'm not sure what attrributes of the Daddies cause them to be pow friendly, although I assume it has to be a combination of having the width to float and the beefiness to not get pushed off.
So what do you look for in a crud ski?