Outside of Raspy, I don't think Snow Storm is all that great for Arcanists. He can't do as much damage as Howard. He can't out-activate better than Mechanical Rider. He can't offer as much mobility to his crew as Angelica or Cassandra.
But in Raspy, he's amazing. He has frozen heart. He can be a mirror for Raspy or her Silent Ones. His walk is high and he can place his friends next to him; an invaluable tool in the glacially-slow Raspy crew. And, if your opponent tries to beat you at your own shoot-out, he protects you. With his healthy number of wounds(and your silent ones to heal him, should he need it), he can be the vanguard of your slow, but incredibly deadly, advance to push your opponent off the board.