I'm watching it and currently up to episode 6 as well. Something I've really enjoyed with the show is how they show his humanity. Yes his skin may be unbreakable and physically he's very strong, but he's not mentally invincible. Without trying to spoil it, this was very apparent when someone close to him died in the early episodes. He has a physical super power but he's still emotionally vulnerable. If they want to cause him harm, they should keep going after the people he cares about and let his guilt eat him alive and exploit the fact that sticks and stones won't break his bones, but words will hurt him (emotionally). My prediction is that this will happen in future episodes, but I could be wrong. This isn't necessarily a new thing with superheroes (similar things in Daredevil which is also a really good show in the same universe and even in the Batman trilogy to a degree, probably in many more things but those are ones that I've seen that come to mind) but I think they have done it better in Luke Cage than other characters. It might just be a minor detail but it's something that really stuck out to me and is a nice dichotomy from the "invincible/strong man" vibe that you get from him.
In addition I also like the style of the show. The frame of Notorious B.I.G. was a really nice touch and having a nightclub as a central location is really cool in my opinion.