Cissokho has never really justified his price tag at Lyon. Had a decent first season and showed some promise, but after that he's been quite inconsistent. He's got a lot of energy and is very fast, but he's not the best defender and his crossing is quite poor too. Still he'd be an upgrade over the leftbacks Juve have, plus he'd allow Chiellini to revert back to his original position as a CB. For the right price i think he'd be a decent move. But only for the right price.