He has experience in an organized defensive team. He'll bring that with him.
Also, Cech is huge- his size, presence and reputation aren't to be underestimated. He is one who is already established as a class goalie. Once he makes a couple of good saves/ we keep a few clean sheets and the media is going to jump on and start mentioning how he's a great addition and how hard he is to beat, which has a positive psychological effect on our team, and makes opposition strikers think twice.
We should sign him at all costs.