It’s an awful lot of fun, this adventure with every Dalek ever and my personal favourite Master. It’s not just the quips or the impactful visuals, or even the bold hooks - of which there are many. It is the quiet character development of Davros which shines through everything else. You see more sides of him here than you get to in nearly any other adventure. He is so much more compelling in this more talkative and contemplative mode than the shouty, gibbering wreck we get in Journey’s End. The bookend with young Davros only enhances this. And I suppose is the closest we’ll ever get to I, Davros onscreen.

The device of the Clara Dalek is neat, it is a smart exploration of how the Dalek’s limited and clearly controlled vocabulary shapes it’s character.

The way the main plot is tied up is almost perfect in concept, but in its realisation it comes across sudden and disconnected, in an otherwise pretty stellar story. A fantastic opener though, and for this viewer a much more promising second leg to Capaldi’s era.

Left alone in a room with him, I would've killed Davros with a hammer, I can tell you that much 🤷‍♂️

I guess I just didn't connect with this second part as much as the first. I liked the scenes with Doctor and Davros, but also feel, to a degree, they didn't really go anywhere with it. I don't know, I just feel after all the build-up of this character and delving into his past along with his relationship with the Doctor, that we were going to do something with it? Instead it just feels like a lot of fanfare over nothing. We get Skaro back, I guess, but I also feel like it hardly matters or ever comes up again. It just becomes a lot of noise. It's like the scene with the Doctor in Davros' chair. He makes some quips, we have some fun with the visual, and then nothing really comes of it. I was a bit disappointed.

I do really like all the stuff with Clara in the Dalek, though. It was both a little fun hearing her voice get filtered, then pretty disturbing and creepy after a while. It was very well done and basically salvages the whole episode. Were it not for Coleman I definitely think the Doctor and Missy's constant quipping would have been overwhelming here.

Another one watch review.

Well that was quite something! There was so much to enjoy. It was high time the daleks had a decent two parter. This one felt satisfying. It was scary. It challenged many conceptions. It had fun moments. There were moments of horror, some new developments and plenty of excitement. Let's take a few of the elements and examine them.

Missy
Not since 1973's Frontier in Space has the Master appeared alongside the daleks and even then it was only briefly. Both were in The Five Doctors, but the dalek was only really a stand alone cameo in that adventure. This time Missy had lots of screen time with the daleks and she was wonderful. In turns charming, irreverent, devious and just plain bonkers, her every moment on screen was a delight to watch. Michelle Gomez has breathed new life into the character. I didn't feel that the revived series ever quite got the Master right, but that's all changed now. She fits the role perfectly and there's no doubt in my mind that this is the same character that Roger Delgado first brought to the screen.

Missy had some wonderful moments: throwing Clara into a hole to find out how deep it was; turning her back to call Clara's bluff about killing her; poking Davros in his eye, to name but three. She also had the most deliciously devious and downright evil moment, but I'll avoid spoilering the whole episode.

Davros
Julian Bleach's portrayal is brilliant. My only complaint is that he isn't Terry Molloy, although he's every bit as good. He had me believing in Davros' remorse and his manipulation of the Doctor. He was chilling and very watchable. The moment when his real eyes opened for the first time was compelling. This was like the moment a dalek was first shown going upstairs. The shock and awe was punctured somewhat later in the evening when I read Sid Trotter's tweet:
Sid Trotter @sidtrotter
 

Davros being able to open his eyes means he'll get his benefits cut. Trust me.

Clara
Clara had her work cut out dealing with Missy in this episode. She started tied up and suspended from a rope and frankly things didn't get much better for her. When hiding inside a dalek casing we learn for the first time that the casing doesn't let its occupant express certain feelings. This is different to the experience Ian had in the first dalek story when he was able to talk without software restraints. Perhaps the casings have changed since then? Had Clara found herself in one of the sixties dalek cases, would this have been the case. too? Again, Twitter provided a plausible explanation:

chiller @chiller
"Say 'you are different from me.'" "EXTERMINATE!" OMG the Daleks are #DailyMail readers. #DoctorWho

The daleks themselves, while looking wonderful, had little to do but watch the story between the Doctor and Davros unfold. This wasn't a huge issue in the time alloted, but had it gone on much longer we might have fallen into the problems that some of the eighties dalek stories displayed; that the daleks were diminished by their creator. This story was more about Davros than his creations, but they still manage to appear in the series without him, which I think was the major problem the series ran into back in the eighties. 
 
The Doctor using Davros' chair was a delight. In fact Capaldi's performance was sparkling. He gave little away, but we saw more light and shade than I felt he showed during all the last season. He's settled into the role and it shows. The longer hair suits his doctor as do the variations in his costume. 
 
I enjoyed the theme of the fine line between being a friend and an enemy. Missy, Clara and Davros are all important to the Doctor and they go back a long way. While there was a little bit of timey-wimeyness in the plot it wasn't simply being clever for the sake of it, which is a criticism that I'd level at some of Steven Moffat's work. This plot had plenty of heart and it was based on character. It was nearly perfect.
 
OK, just to show that I can find something to pick at, I didn't like the episode titles. They didn't seem to relate to the story on anything more than a tangential level. But as they came attached to the best dalek story since Dalek, I'll live with them.