Spoilers ahead, of course.
I liked "Orphan 55". It was fun, full of action and suspense. It had a cast of supporting characters who for the most part were well-drawn and made you care about them. I came out of it smiling - well, almost, but I'll talk about that later. However, it was plagued by niggling problems that are far too easy to nitpick and unravel.
It started on the surreal side, which is always my favorite style of Doctor Who (harking back to "Gridlock" for me), with a large helping of humor. This episode made me laugh out loud a number of times. It spent a good amount of time establishing the setting of Tranquility Spa and backgrounds and personalities of the staff and guests. Once the danger became apparent, the action rarely stopped, and mostly only to ratchet up the suspense factor. As I said earlier, it was fun and entertaining.
The problems emerge when you start to really think about the story. For example, what did the Dregs really want? Did they just want the piece of land back, and if so, why were they so insistent on hunting down the people? Were they out for food, or perhaps they simply wanted to hurt/maim/kill the living people in the dome? If so, why did they carry Benni for so long? We can explain why he survived outside - he breathed the oxygen that the Dregs exhaled - but why wasn't he terrified and panicking when he talked to Vilma, or at the very least, why didn't he ask for help? Why did the Dregs allow him so much time to have a pleasant conversation?
I'm also really not sure why they found it necessary to pack every single person into that van and leave the dome. It didn't seem like the dome was in danger at the time they decided to chase after Benni, and bringing Vilma and Silas seemed like a major liability, but maybe I missed something in the dialogue. I definitely need to watch this again.
Then there's Kane and Bella. It seems pretty far-fetched to have a daughter hate her mother for leaving her so much that she's willing to blow up her mother's life's work, most likely killing everyone involved including herself. To me, it felt more like the writer dreamt this up to create a reason for bombs to be planted all over the complex. We could also go down the path of Bella's plan also involving having to earn all six randomly-distributed pieces of the cube to get in position to plant the bombs and somehow get those huge devices transported with her to the dome. But then, I'm also not clear on how exactly this resort made Kane any money, as it was stated many times that the guests got everything for free. Ah well. This is truly nitpicking.
And the Dregs again -- just another slow, roaring monster. Sure, they looked hideous, but once we actually got to see them in the open, they were no scarier than, well, all of the other slow menacing monsters. The show probably would have been better off keeping them in the shadows and only letting us catch glimpses of them as they stalk and catch victims. Perhaps a rocky landscape or tons of dead trees that the humans can't really see through.
I think however, the main problem with this episode was the ending. A friend of mine (who hasn't watched DW in years - he was a big fan but couldn't stomach series 8 and stopped halfway through) mentioned a few hours before I watched the episode that the reviews of the season had complained that DW has become too "woke". I waved that off, saying that DW has never shied from making political and moral statements, mostly on the liberal end of the spectrum, and that people were probably just upset because Barton's speech in "Spyfall" had hit too close to home. Then we got the end of "Orphan 55" and I understood what they were saying.
The thing is, the problem with "Orphan 55" is not that DW is trying to be an SJW. It always has been. The Doctor has always battled oligarchies, societies that marginalize their minorities, and creatures that destroy, whether actively or passively. The problem with the episode is how it communicated its message: it told, not showed. Earlier on, through the story, we and the characters discovered that Orphan 55 was Earth, destroyed by climate change and abandoned by the people who could afford to escape, leaving behind those who were too poor. We got to see the effects of this, and the TARDIS team's reaction to this revelation. Then, when the story was over, the Doctor reiterated the message in a lecture to her fam. The first was perfect, and the second left the episode feeling like you were sitting facing the corner after being scolded by Mom.
It's the storyteller's first law: Show, don't tell. Show the audience what happened and let them make up their own mind; if you've done your job correctly, they'll get the message, and if you've done it well, they'll learn. Lecture them, and they'll automatically resist.
There are a couple of opportunities that the episode passed up. The first was using the love interest/saboteur to build out Ryan's character: it should have been Yaz. We've had a whole season about Ryan, but Yaz is still completely undefined as a character. This was a fantastic chance to have her interact with people outside of the TARDIS team and show how she would handle her love interest revealing her murderous intentions.
The second was a bit of fan service. The current show seems to not like making references to the past unless they are completely obvious, but in my opinion, subtle references are gems, rewards for loyal, sharp-eyed fans, as well as provide a stronger sense that the Doctor is the same person that we've watched for 56 years and remembers her past lives. The Doctor's in a bus with no windows, traveling with a bunch of strangers on an uninhabitable planet on which someone's built a resort, with monsters knocking on the sides? Perfect opportunity for a mumbled, "Oooh, flashbacks..." from the Doctor as she tries to shake the thought from her mind. Or someone could have repeated something she said and she goes, "No, don't do that. Don't. Don't."
So there we go. Good episode, but brought down by niggling issues and a botched ending, but both are ignorable to some extent. I'd say 7/10.