For me he has not met expectations and the only time he has noticeably given 100% and carried our team to an extent was in the lead up to his Xmas contract and injury last season. Apart from that he has given closer to 75% than a 100% (I think he struggles with motivational issues)
If we had done more in the summer window than just buy a gk in 15/16(or even strengthened in january), Özil would have been the main man in a title winning side and the narrative would have been totally different, he was performing as one of the best players in the league at the time. He's been inconsistent, but has had plenty of periods of good performances here and I'd argue his best form as a footballer individually has been with us.