Armia plays high event hockey, lots of takeaways lots of giveaways, I'm not checking stats but judging from what I've seen of his play. He has generally played a lot better on good teams, like during the cup run, and in international play. My take is that his motivation, and his style of play, is a lot better on good teams.
He breaks up a lot of plays and generates a lot of loose pucks in the neutral and offensive zones. Good teams will grab those pucks and get scoring chances, while bad teams won't be able to.
I think Armia's a good player to have around at his current salary. He brings some abilities the habs generally lack. He's a bit old for the rebuild, but he's not one of the guys who just has to go before they can compete. Even Gallagher has looked better the last few games, he's not damaging the team with his play lately. It's mostly about dumping Gallagher, Dvorak, and Price now, though, just to be able to use their salaries to get one or two really useful players. The LTIR is fine, but it's an obstacle when the season starts.