Finished the season, loved every moment of it. I liked it better than DD or JJ for the simple reason that the protagonist was likable.
Cornell was a great antagonist but had to go after the first half of the season. He was always going to be the first step that Luke Cage climbed up and over. Cornell himself was an overachiever who scrapped and clawed everything he could and took favors from everyone who would listen to get into a place of power. As soon as there was an issue he would be out of his depth and crack. It's why he had so much focus on being the "king" because he wasn't confident he deserved or could hold onto it.
Whether it was his character (I don't know the comics) or just Mahershala's acting I don't know, but I really enjoyed the genuine laughs Cornell would produce when threatened or insulted. It gave the character a sense of humanness and levity, and betrayed that he wasn't in control of the situation even when he had a room full of armed guards in his castle.
If I had to make one criticism, I didn't think they set up Diamondback correctly. There was too much disassociation between his character and the character they built up before. He seemed to fit the role of Deathstroke in the Arrow series: Hyper-intelligent maniac bent on the absolute destruction of the hero and using a criminal enterprise to do so. However, every seen with Diamondback showed someone who could only destroy and ruin, not set things up. Everything he touched went to shit.
I know they were setting up shades (Who I thought was miscast, Theo Rossi just didn't seem menacing or cunning though they writers/directors tried), but they should have let Diamondback do at least some of the smart work. Or there should have been a scene at the end where Shades explained that he was just using Diamondback as a puppet for his connections or whatever.
Luke Cage himself was perfect. Strong enough to be enjoyable, thoughtful enough to be personable. The action scenes lived up to what the trailer suggested. There's a superman like difficulty in creating interesting and challenging fight scenes with a man who can't be harmed by any weapons in the scene, but I thought they did a good job and even in the last couple episodes him walking through gunfire was entertaining.
The juxtaposition of the action scenes with the music was the highlight of the show. I don't think any TV show has even tried to accomplish the same integration of great music being played by something in the scene and an action sequence. When I was halfway through the series I remarked that I wasn't sure if 100% of the music was played by a scene object, which would be ardorous on the level of having 5 minute fight scenes in apartment hallways. This wasn't true of course, but all the big music scenes were.
I saw mixed reviews in this thread for the series, but I hope this TV show is successful enough that in future versions of DD and JJ the writers decide they don't need their characters to be miserable all the time. I'm pretty pumped to see another season.