You can't say he's miles better than Sagna. Or Zabaleta for that matter.
He's a good solid player but not even close to the class of those two, for me. Especially Sagna, who's got his side of the pitch on lockdown for 30+ League games a season and has done for nearly 8 years.
Grass always appears greener with opposition players. But that's because every mistake they make doesn't hurt or anger in the way it does when it's one of ours. Sagna really is top class.