Canadian coaches categorize racers in several well defined levels, each with well defined objective criteria, based on specific tasks. You can lookup "snow stars" online for details.
Personally when looking at the recreational skiers, I tend to categorize them based on the ability to carve clean slalom turns on a green, blue or black run. That's often enough of an indicator. You would be surprised how very few people make it to the black...
I realize that's a reduced scope, but it's the same with cars and everywhere: a good F1 driver has different criteria than a drifter or a monster truck driver... I'm not going to blend then all into some idealized thing and make up some scale, perhaps one where I rate high...
Fast cannot be a goal unless you're on a course with some obstacles... otherwise it has no meaning, really... what, a tucking contest
For me, my purpose and goal is to understand skiing as deeply as I can and then ski as efficiently as I can.
Style is not relevant to me, I see it like more of a constraint than a tool, so I try to be objective.