This guy is a stud from everything i've read. He was almost unanimously ranked as a late first to early second rounder (20-40)
Skating, and the Russian factor is probably the reasons he fell. Apparently he's super shifty, just doesn't have the top end speed. Another 20 or 30 healthy pounds on his frame would help his explosiveness a ton. 6 foot 163 lbs is frail as hell.
There are reports questioning his compete and effort level, but that's usually the case with a dangler. Kovalev has those doubts his whole career, but it was extremely overstated. I would have to see him myself before buying into reports on peoples effort.
He's top 6 or bust, but I think letting him marinate in the KHL for 2 years or so, and then getting him a season to adjust to N/A hockey in the AHL would be perfect. And the Knights are a great team to let him slow cook. There's no room in the top 9 until someone like Patches starts winding down or traded, so Vegas can stash him and just let him develop naturally.
Now that I think about it, another good comparison would be Gusev. Super talented offensive playmaker types with underwhelming skating.