I liked it so much because of the slow but tense rhythm of the history, the details of the characters, Atkinson being very accurate of the very heart of Maigret, but even more, giving power to the character. The secondaries and cast are very good too.
Only Poirot and a handful of TV mystery dramas can compare with this.
On the other side, the only thing I can say is that it looks like London, not like Paris, besides the effort they do to translate everything on the screen to french and use of the stone paved streets.
Congratulations to the team, the script and everyone else.
I hope the today's TV learned something.