I guess I could argue that Kyurem isn't meant to really sweep as it is to break walls since it honestly can't sweep in OU unless you use Scarf lol.
Using Roost also limits your coverage to Draco Meteor/Fire Blast, and either EQ (walled by Blissey), Brick Break (still only 2HKOes Tran), or Outrage (walled by Heatran...), kills the whole Salamence has better coverage argument. Granted, Dragon Dance is a huge asset.
I don't think Salamence is better, but I don't think that necessarily means Kyurem is better. I was just pointing out its not outclassed and both can work well. Depends on if you want Dragon Dance and Fire/Ground moves or a better time against Grounds and Waters.
What Kyurem sets HAVE you used in OU, btw?