Right off the bat; he is worth every penny and I would know because I overpaid for him. "The price justifies his performance", that is what I tell myself; that's how good he is. Put an anchor on him and he'll run even faster, and defend even better. He will intercept any through ball, his speed catapults him in front of sprinting attackers and the smart AI cuts off the passing lane 90% of the time. Additionally he will stay back. Unlike *cough cough* overrated van Dijk. Running towards the attacker he will 99% knock off the ball. Giving attacker space he will be able to keep up with their dribbling. Don't mind his reactions and aggressiveness too much, his AI is much smarter than on paper and strength and aggression improves with Anchor Chem anyways. He might lack in the stamina department compared to other defenders but it is enough for a full game. However, you will have to fill up his fitness more often than other defenders. Not to forget he links up with van Aanholt, who is another defender better than on paper. As for passing you just look at his short and long pass. You'll see that again his passing is better than on paper. You don't need defenders to cross or anything like that. To sum it up: Smart AI, fast and agile, better than what the stats say, but he needs an Anchor Chem.
1000% better with Anchor
prices are sinking
Reactions and Aggression could always be better (not a huge problem, just switch to Aggressive Interceptions)