For me, just like a couple of other players, his mistakes outweight his good moments. I remember him having a great game against West Ham (although, really, he mainly just did what a defender is supposed to do), but those kind of games are few and far between with him. Small mistakes are fine and only natural, but when they cost us goals, then they really need to be ironed out. Unless he does this soon, then he'll always be a 3rd/4th choice CB for me...