I watched (one of the only Chelsea games that I have seen this season mind you) them against City and suffice to say that this specific performance by Chelsea and Sarri (tactically speaking) was impressive. Since that result it has gone downhill for them.
However to be honest they don't even have, remotely speaking, the best squad out there. Man City, Liverpool and even Man Utd all have better squads on paper. Chelsea's best goalscorer (on paper) currently is Higuaín FFS.
Sarri being Sarri is not helping either. He has reportedly clashed with not only the team that he publicly threw under the bus (that usually does not end well for the manager) but Abramovich as well.
Anyway I don't dislike them as much as I used to do when our rivalry with them was at the highest (those two appalling semifinal games back in 2011-12 did not help either) and Chelsea is a nice area of London but I can't say that I am sad about their current situation.