Personally, I thought this week's episode was good but not great. Thankfully some advanced reviews suggest that this is the weakest episode of the first six, so it's uphill from here.
There was a lot here to like. I enjoyed that not only Una, but Pike was sidelined this week, allowing for the focus of the episode to be on supporting crew. This was really a Spock/M'Benga/Chapel episode, with a somewhat lesser focus on La'an and Uhura (as is usual, Ortegas was a quippy nonentity). Spock had a complete character arc here, even if the framework of the story somewhat counters what we know from The Galileo Seven. A lot of the small character moments were great as well.
I was more mixed on the idea of M'Benga and Chapel (I think) not only being Klingon War veterans, but taking some sort of super-juice and turning into action heroes. It felt like a decision not rooted in what was established regarding their characters, but the needs of the plot and a desire to buck convention. It also made somewhat little sense to me that not a single Klingon was armed with a disruptor or anything, because that would have turned the action scenes into something much less visceral.
I also felt like some of the dialogue was just...bad here. Most of it was fine, but there were plenty of "as you know, Bob" type lines that were clearly only there because some fact needed to be established for the audience. It's a major failing of show, not tell. Star Trek always tends towards a bit of exposition, but that's what group meetings and the like are for.
Also, the new engineer (Pelia) feels like she walked off of another show and clashes in every scene she's in (feels like a "poochie"). I don't know who instructed her to use that raspy Eastern European voice, but it sounds appropriate to play Baba Yaga, and doesn't match with the pretty understated costuming of her character. The lines as read on the page, they're fine, I just think Kane's being directed horribly in regards to how to present her character.
She recreated a voice from a character named Simka from a comedy called Taxi back in the day. It was funny then, but not now.
That said, after three paragraphs of nitpicks, this was still an entertaining hour of Trek. Just not the smartest hour.