No surprise Sunderland look miles better since Cattermole has come off.
I think a lot more of it is to do with the change of the shape of the team, rather than one player. It was the same against us. They sat back and were poor, unadventurous. But, when they sacrificed a defender and actually went out to try and score goals, rather than not lose the game, they were instantly a better team.
Sadly, they are not good enough defensively or offensively to steal a 1-0 playing 5 at the back. If I was a Sunderland fan, I'd be looking more at Poyet's initial negative tactics, rather than Cattermole's contribution.