I genuinely believed he's a terrible signing, even for the 300k Wolfsburg decided to sell him for. Mostly due to his terrible form in Germany where he was a laughing stock. His last years in Palermo were also bad, as was his first (half) season with Juve.
It was like he was a talented CB who made it to the 2006 WC squad at 25, then he had really bad 5 years (which is like 1/3 of a player's career) and at 30 the big talent finally showed.
One doesn't get that lucky with 30 year olds so often. But back in 2010/11 it really felt no different than signing Zaccardo (another 30 year old who won the WC with Italy at 25). Actually, Zaccardo was a safer bet back then.