He's a player that shines when he's surrounded with quality, not a lone warrior like Vidal or Tevez. He doesn't significantly raise the performance of a mediocre team, but put him in a squad with a few WC players and you'll hardly notice that he wouldn't normally belong in there.
As he's primarily a rotation player, and at Juve he's likely to be surrounded by quality 95% of the matches he plays, that's perfect for us. And considering his age, he might even improve into something better.