I'd only want to keep him if there's any chance of playing him as an actual winger, be it in a 4-3-3, 4-4-2, doesn't matter. If we only use him in 3-5-2 then I'd rather we get someone who can defend better.
And comparing Cuadrado to Berardi doesn't really make sense, so please stop. We can have both, they're different players playing in different positions. One is a striker that cuts inside from the wing, the other is a wide player. You can't play Cuadrado as striker just like you can't play Berardi as wing-back.