I can remember a couple of important tackles and interceptions which got him a big cheer, though. To me he really is playing that well.
His marking and positioning is excellent. Quite often you see the other team look to make a pass out to their left, but they think twice because Barzagli moves in to make it impossible. And even if they do pass it his tackling is excellent. He also has great vision and makes the right pass out of defence. Plus he's surprisingly quick as well as strong.
These together make him the best CB in the world at the moment