1) A lot of people complain about DANNY RAND's personality. The beginning of episode 6 shows that there's a reason for him to be that way. What I don't know if this was a response to the criticism of the IRON FIST series or if it was planned before that series.
2) The series has a stylish element that I'm sure you've all noticed: The color palette. DAREDEVIL is red; JESSICA JONES is blue/purple; LUKE CAGE is yellow/gold; IRON FIST is green; THE HAND is white. If a scene shows only one of the heroes or only the villains, their color is highlighted through cinematography and/or production design (although most of IRON FIST's scenes looked more like blue to me). If we see 2 or more of them, there's a mix but one always predominated. The most creative use of this in the entire series was during the chinese restaurant scenes. They were beautiful to look at!
3) When STICK posed with the others at the end of episode 4, I thought it was a way of showing that he was a DEFENDER as well despite not being advertised as such (it happened with 3 certain characters in GUARDIANS OF THE GALAXY VOL. 2). In the end, he wasn't... so why include him in the first (of very few) posing shots? Those matter a lot in the super-hero genre.
4) It's not that common for crossovers to include supporting characters from each series/movie that aren't super-heroes or super-villains... let alone have them interact with one another. That's one aspect (and maybe the only one) in which THE DEFENDERS is better than THE AVENGERS.
5) The arrival to the building in episode 7 was the series' worst moment! The long takes were replaced by shaky cam, dark lighting and choppy editing. It would've been tolerable if it had focused on DAREDEVIL, JESSICA & LUKE or on IRON FIST. Going back and forth between both fights made it even harder to tell what was going on!