Well, I don't really know what to say about this episode. I'm really not sure if it's positive or negative either, so I guess I'll break it up into what I liked, and didn't

LIKED:
- The VFX were again top notch, the best we've seen in Who till this point.
- The Master was completely unhinged, and great as always.
- Jodie finally has some very dark and emotional scenes, and she does them wonderfully.
- The companions were top notch again, and that scene between Graham and Yaz was beautifully written
- I did like the exploration of early Timelord history, (even if it doesn't gel that well with previous knowledge.) The Timelords getting regeneration from another dimension/universe is an interesting idea

NEUTRAL:
- Pre-Hartnell Doctors. On the one hand, I'm against the idea because of how it feels like it disrespects the character arcs that the Doctor has gone through, (and the continuity issues it presents.) On the other hand, I think it's a neat idea that the Doctor has a hidden past that she's now aware of, and that can present some interesting stories.

DISLIKED:
- The Doctor being the Timeless child... why, oh why? Originally the Doctor was just a "cosmic hobo" that we followed along through time and space, and now she's the most important person in timelord history?
- The Timelord Cybermen were a bit.. out there concept.
- Ashad getting shrunk was very anti-climatic imo.
- The ending twist and cliffhanger was very abrupt

I'm probably forgetting something, but I think this was a decent finale and episode. I can understand why many don't like it, and why it's called the Master's powerpoint presentation. Will have to sit on it longer for some more thoughts.