Without a doubt Arrmia is the key piece to this trade, if he's not NHL ready right now then he's pretty damn close from what I can see. Lemieux is going to be a few years away and does not have the high end puck skills Armia possesses, he's a great secondary piece but that's definitely what he is.
I would love to see the Jets give Armia a shot this season, give him a few games to get his legs under him in St. John's. How is not an immediate upgrade over Thor? He looks to have the size, speed and offensive talent. I wouldn't expect him to light it up or anything but he's going to bring more offensive attack than Thorburn. He's not a 4th line type guy, Thor can do that job, we need creative players like Armia to round out that top 9.
Given the alternative, I'd like to see them give it a shot.