As a fan of both Star Trek and of musical theater, I was okay with the episode. If I had any real complaints about the musical side of things, I'd say that the lyrics were often rather clever (I loved the opening number "Status Report" which included and rhymed a fair amount of technobabble) and generally the music was pretty good, but when you announce not just a Big Ensemble Number but a Grand Finale, it should be a Grand Finale. I really wanted that closing piece to blow me away, but honestly, it was a little on the weak side. Musically it was on par with the some of the earlier ensemble pieces, but if I were ranking-obsessed (as many DTF'ers seem to be) I'd put it somewhere below the median overall. Some of the solo numbers were pretty good, some not so much. But what the hell, it was fun.
I'm still trying to connect dots and storylines between what we're seeing here and what happens "later" in TOS. I want to believe that this is in the same timeline and that there will be continuity, even if it hasn't been explicitly stated (or has it?) They seem to be expanding upon canon, occasionally bending it a bit, but there seems to be some care taken to honor TOS canon and not outright contradict it. I can still see how Spock and Chapel end up where they are in TOS. After this painful breakup (which he wasn't even sure was a breakup at all, but clearly is now), Spock eventually decides to go "full Vulcan" with his emotions and furthermore to treat Chapel as a shipmate and nothing more. Chapel goes off to study with Roger Korby and they get involved but it obviously doesn't work out. She returns to The Enterprise and finds that she still feels something for Spock, but he's having none of it.
Dr. M'Benga's exit was set up last episode when he killed that Klingon ambassador. Self-defense or not, killing a diplomat is generally not a good career move, and there's a reason why he's on The Enterprise in TOS but no longer Chief Medical Officer.
The La'an-Kirk thing is weird, but we got our first name-drop of Carol (Marcus obviously) and that she's pregnant with David. I think that this was basically the end of the La'an-Kirk thing.
Poor Captain Batel. Off to some Priority One Mission or something, with only one episode to go in the season. She's a goner.