I somewhat disagree. Even 2 years ago when he had his 31 goal season, that was done in a run-and-gun system in Buffalo where defense was an afterthought. And even then he was really bad defensively.
His one year (out of 5 seasons now) was done where his shooting percentage was an outlier, in a system where he didn't have to play much defense, and even then the goal number overshadowed poor overall play.
The Fans in Buffalo, some of them like him and they point back to that season, but the guys who break down replays or go to the games in person and follow him around, the guys who post who look at his play without the puck, he's always been substandard.
Even his 'best' year he was a minus player on a team where Thompson, Skinner, and Tuch were all postive players, some of them double digit positive. Cozens and his linemates were minus players. Whenever his linemates change, the new guys on his line turn into negative players where guys who leave his line turn into positive players. That happened even in his 30 goal season. Its pretty much the case every year for him, without fail.
He might be a useful pickup, but he can't be a center anymore. Let him play wing and let him crash the corners in the offensive zone (which he likes to do) but make sure you have a responsible center for him. And keep him on the 3rd line and do not put him on the PP.
He might still thrive in that role, but is that worth $7m per year?