At an even salary, I think Chicago is better off with Saad over Panarin, especially with the loss of Hossa. We need another body that will go to the corners, the front of the net, that can play a regular shift in the top 6.
Panarin was great, and could score a bunch of points, but outside of that, he doesn't help the Hawks much (He was getting too predictable on the PP, doesn't PK, play defense, or play the body much at all). He's a perimeter player on a team full of them. I don't think the Hawks offense misses a beat with Saad instead of Panarin, but without Hossa, our team is worse defensively, and that had to be fixed.
I am OK with this trade, Panarin will probably still get his points, and Columbus needs a player like him more than they need a player like Saad.