I've been pleasantly surprised by what I've seen of / read a out Sokratis over the last couple of days. A lot of the compilation videos make him look like a bit of a nutter who loves diving in with a hard challenge, and who appears to play the more advanced, aggressive CB role (like Kos and Mustafi) - however, when you watch one of those videos that follow his contributions across a single game he comes across as the exact opposite: a very calm, composed presence who comes across as more of a Mertersacker type. (I think his stats show that his interception rate is quite low, so that's a good indicator that he probably plays as the more withdrawn CB in a pairing.)
Don't know if it's true or not, but I heard someone say that he's only made 1 defensive error in the last 4 seasons! I can't even imagine what that must be like after watching our lot for the last couple of years?