Remember, if you want to watch the episode, do that first, because I'm not marking any spoilers.
The episode starts by building off of the ideas from the S4 finale, and as I said about that episode, I really appreciate how they're maintaining an ensemble cast in spite of Twilight's new status. Even better, this is the first bookend episode since "The Return of Harmony" to not put most of the emphasis on Twilight. Each member of the mane six is of equal importance, and even when one of them is singled out for plot reasons, it's not Twilight, but Fluttershy. S4 had the problem of making the bookends the major Twilight episodes, so with this one not focusing on any pony in particular, there's promise that some of the smaller-scale episodes may have Twilight as the central character. Considering that one of the best episodes of the show is a Twilight episode, that's promising.
However, although character roles were done very well, the characterization itself is unfortunately a little iffy. Rainbow Dash seems even more brash than usual, with her increasing maturity over the season apparently not translating to common sense, even though she honestly should have more of that at this point. Fluttershy, meanwhile, doesn't express much timidity throughout the episode (which is really satisfying after S4's complete misuse of her), but also acts really bizarrely as she takes a liking to the feel of the town... for some reason. It's a decision in service of the plot, but also a really strange one that doesn't seem to make a whole lot of sense.
Most of the other characters are written far better, especially the always-amusing Pinkie Pie. Some people take issue with her increased silliness over the past season, but for me it was always one of the highlights of S4. Applejack, meanwhile, hits the perfect balance of earthiness and silliness, and Rarity has her high-minded interests while still being level-headed. Twilight Sparkle is characterized as well a she's been in S4, which unfortunately means she's sort of a non-entity. Compared to the first few seasons, Twilight's been kinda lacking in personality, and I maintain that her best characterization in years was in the Rainbow Rocks movie. As she is my favourite character, I find the generally underwhelming writing on her to be disappointing.
The most unique thing about this episode is its heavy use of dystopian imagery. For a children's show, this is a particularly odd choice, but it makes an impact and drives home the main point well. While many have seen a statement about the line between egalitarianism and totalitarianism in the story, it's also a really basic one which is at least older than Kurt Vonnegut's short story Harrison Bergeron, which was intended as a satire of the ideas which "The Cutie Map" seems to play straight. The political ideas aren't particularly nuanced or even all that well thought-out, but this is a kids' show. However, considering the target audience, I'm not entirely sure this story had the intention of being political commentary, and thankfully, there's much easier and more solid themes to be found in the episode.
First of all, it's a celebration of individuality. The message that gives kids is that they should be proud of who they are, and that it's who they are that makes them special. More than that, though, I think the main message of this episode is that it's understanding each other's differences and being able to disagree without becoming bitter that makes friendships strong. That ties back to the overarching themes of the entire show, and many of the stylistic choices actually work in service of it. And hey, if the writers did intend this to be a child-level political commentary, more power to them.
The antagonist, Starlight Glimmer, is the third parallel for Twilight that we've seen, after Trixie and Sunset Shimmer. In terms of subtlety, she's about on the level of the aforementioned Sunset, though instead of having a similar backstory she simply has a similar talent, a brief reference to having studied magic, and a somewhat similar colour scheme. As far as antagonists go, this one isn't particularly deep, but she does have the advantage of being straight up infuriating. My Little Pony has never quite made a villain completely and utterly loathsome before, but Starlight definitely possesses those traits, not just because she spouts a bunch of nonsense but also because she's clearly trying to overcompensate for some sort of insecurity. This makes the episode all the more engrossing.
Aesthetically, the episode is one of the most gorgeous yet, possessing all the lessons learned up to this point about framing, palette, and lighting as well as extremely smooth animation. However, this is countered by some moments that just look... weird. One particular moment with Pinkie Pie seemed a slight bit grotesque for this show, though it's one small moment and she gets better. A lot of the episode's style is based on the uncanny valley, and indeed, this episode is one of the creepiest yet, arguably matching "Lesson Zero" in the discomfort factor. That is quite the achievement, but "The Cutie Map" makes it work.
In a first for the series, the episode actually has a slightly open ending. We don't know what becomes of Starlight Glimmer, and this is an intriguing turn of events. What will become of her? We can only guess at this point. Another first for the series is that minor characters aid in the final confrontation. This is particularly interesting because it opens the floodgates to all sorts of possibilities, up to and including speaking roles for fan-favourite characters. What they do with that, as well as with the changes in structure, remains to be seen, but it's immensely promising.
And that's the final verdict on this episode in general. It's not a perfect episode, and isn't quite up to bat with the bookends of the first two seasons, but it does match the S4 premier in quality, and boasts even more promise, especially without a mess created in the previous season to fix. This could very well be the start of something great. Let's just hope that they don't go too far with it.