Please be aware I haven't seen the original series, didn't even know it existed. Didn't know this was adapted from a book either, so I'm reviewing this as if it was the only thing out there.

I think the best of this show are the way it's filmed, the general atmosphere, architecture, the inclusion of naginata (damn finally) and the clothing.
I have to give kudos to the architecture, atmosphere and scenery especially since, as far as I know, it was mostly recorded in Vancouver area, so to pull something like this in such a completely different place it's amazing work. But, I also have to admit that it took me out of the story a couple of times when I did recognise a couple of landscapes as someone that has been in the area as well as the fact that while certain landscapes can pass for areas of Japan, others were a bit of a stretch.
The plot keeps you invested most of the time, but it does suffer from being a bit convoluted at times and slightly dragging at others when it seems it doesn't know what it wants to do next, as well as that general repetition in the execution of leaving most of the action and interesting plot points to the last couple of episodes. The atmospheric shots and general vibe are amazing though and I enjoyed them a lot.

Acting was generally very good although I do have to agree with another review that Anna Sawai is the one for me that gave the most of a contemporary vibe compared with the others, but it wasn't very jarring as to be a constant reminder.
If you're looking for a Japanese production this is not it, and I do think there are things that are done in the way they did because of budget constraints. This could very well change for subsequent seasons considering the international acclaim.

The main reasons why it doesn't make it a 10 for me are:
- Echoing what I said before, the plot can be convoluted at times.
- I know they're going for the serious stern look but I missed a bit more emotion (other than the ones from John being too much the opposite at times).
- I'm never a fan of shows with the token westerner that is supposed to be the main character and that become the centre of the universe even if based on real life. While I think they did a much better job here than in others I'm still not a fan, plus this brings me to:
- The worst character for me was John Blackthorne. I'm going to assume this is a mix between what was asked of the actor and his acting. He gave drunkard vibes in his mannerisms and way of speaking. At points I was not sure what the point of him was, and I'm still not sure I get it. I also don't remember him being a ship engineer/builder so why it's that task put onto him in the end, I just don't know. I read the real life figure that inspired the book version was indeed a ship builder, but in the show I can't remember ever being mentioned.
- The fact that they decided to go with Japanese language for the majority of the show is absolutely great, but it pisses me off that the times when they're supposed to be speaking in Portuguese they're in English. At the beginning it was very confusing at times and at some point even if you're assuming it's Portuguese you really don't know anymore. We are to assume that when John is speaking to someone just because (even though he knows they don't understand him) he's speaking in English because it's his mother tongue and he's alone so to speak, but maybe he's trying in Portuguese? We'll never know.
For a show that decided to go for realism with the Japanese language it's a big disappointment it didn't go all the way. People are already reading subtitles anyway, what are a few more? I want the whole experience, not only half of it just to please Hollywood.

If you like historical fantasy, politics, power struggles, good atmosphere, retro feel and good costuming I would totally recommend. Aesthetics are on point.