To the OP : one of the companion's mission is missable too, if you don't trigger it soon enough. I like that too. It makes the world seem more complexe and less player-centered.

Overall, I've been a bit disapointed by the game. I expected something slightly longer. More content and less redundant prose.
The writing stacks up on trivial moments and on the other hand it misses opportunities to raise the epicness at more important times ; e.g when you enter the walled city in the end, the desciption could be far more spectacular and the writer's style suddenly becomes minimalistic.

My biggest disapointment is with the combats. I usually play games at normal difficulty and here I had to raise it to hard. And it was still much too easy !
The AI is idiotic, it seems that it got worse, much worse than before. Only with the ASIST mission did I feel the excitement I remembered from Dragonfall 's fights.

Personnaly, I liked the new matrix. And the graphic art and music were very well done, again. Maybe even better than on Dragonfall graphically speaking. I likes the story and loved the companions (good point for the writers). Gobbet, Gaichu and Racter are great characters. As is Kindly. Raymond is a bit thin though.

I absolutely hated the new matrix - turned a boring thing into a tedious boring thing.

The graphics aren't just maybe better than DF - looking at both back to back, the graphics in HK are massively above that of DF. Not that DF was bad in that regard, but you really notice the difference in the amount of detail that was added. I just wish they'd put the same amount of effort into the combat AI and some of the mission flow.