Well to put it into perspective the Scudetto he won with Milan in 2011 was there first since 2004.
His management at Cagliari was fantastic. He played good football and led them to consecutive top 10 finishes and that is a squad that did not have the quality to be there. He nurtured many players.
At Juventus, in his first season he came close to winning a treble (which would have made him only the second manager to win this with an Italian club).
He's 49, a fantastic age for a manager. He worked his way up the Italian football pyramid and now deservedly manages the best club in Italy. Despite opposition to his appointment, he has been a resounding success.
Some of his duels with Pep's famed Barcelona team were so fantastic to watch. That Milan team never should have been as competitive with that Barcelona team as it was.
If his CV doesn't impress you then I can't quite fathom what kind of CV you must be looking for.
He's a champions league finalist, a multiple time domestic league and cup winner and has a penchant for playing nice football but also organised football. Nurtures young players well too.