If you are told that this one of the better yuri mangas, then you'll probably expect too much. For me yuri is basically a more challenging romance, the thing is that this manga's focus isn't the romantic relationship, but the daily lives of our couple. In essence this is a Slice of Life manga about high school teenage girls doing their best to be cute through appearances. If you like conversations about cute make up, cute shopping, cute dresses, cute hairdos, cute faces, cute school events and basically cute girls doing cute (commercialized) things, this is the manga for you. This is so because the romance gets scarce development between the daily activities, which overshadow it. Near the end of every volume, you're reminded that this is supposed to be a romance between two people who are not used to it, yet are as close as they can be in terms of friendship. As he tags mention, it's better to approach this manga as a Slice of Life with romantic elements thrown in, rather than a Romance that takes its time.

The art is serviceable, but seemingly busy due to how often 3+ characters are in a scene. It's more often too busy for its own good and has a lot of background conversations laid in a small panel, it's excessive, noisy and doesn't contribute much in terms of presenting a scenery, atmosphere or a feel for the setting our characters are in, at least aesthetic wise. The ending impression is that their lives are filled with a lot noise, that is, if you're also counting their own monologing about the state of their relationship, which would usually take effort for someone to space out as such. But in the end it does its job at presenting cute characters in a pleasant manner and keeps it safe.

As a Slice of Life, there isn't much story to go around. Again, it's 4 girls being materialistic in conventional ways, talking about make up, clothes, boys, hooking up, how cute the other looks, etc. The school setting at least provides non-club activities like the festivals, field trips, vacations, so the setting often feels varied and there is a certain feel of a timeline in that regard.
Now it's the romantic plotline that gets the short end of the stick, it's the usual avoidance, unrequited emotional responses, jealousy, mixed signals and so forth. But again they are only truly explored in the end of a volume and just laid to the background after a new volume begins. They are present and mentioned during all the fluff, but mostly in monologues, kept there right before the climactic kiss for the volume ending. And when Akko and Mari(our main couple) really try to dedicate themselves to their relationship, it feels wholly different from what you've been reading up to that point, it's basic, it's cute, it works, but is done for a few pages, not for an entire chapter. That is, if you don't count them going shopping and eating as dramatic relationship development. I see it as SoL fluff, challenge and perseverance are what give strength to character and are testaments for your dedication to a relationship, you either give up or give in to your emotions. Such drama is also left scarce, instead it's replaced by embarrassment half the time, which is understandable, but having only that feels like a cop out, even worse, just a tease. A tease for the reader, not for the characters. It wasn't until the next to last chapter gave us a full on sex scene, but even then it felt out of place and too different from what I've been reading up to it. But at least I'll give the last volume the best feeling for how a lasting relationship with progress feels, where our couple feels inseparable even through graduation and the goal is to stay together. That's what I've been asking for the entire time, but it's too little, too late for something basic to make up for lost time.

The characters are very two dimensional. Even our main couple don't feel like they have truly developed. This is also due to the author switching perspectives, but not altering the writing style in accordance the the supposed personalities of the characters. Mari-chan is the introverted bookworm who is lifted up an taken in by Akko-chan - the extremely friendly, cute girl who likes make up and dress up, on top of having the top of the line materialistic image of herself, well, mostly. Sugi-san is the embodiment of that stereotype, on top of having 5 boyfriends and managing them. And finally there's Tamami who is essentially your cute otaku to make references with.
For a supposed introvert, Mari easily became part of the group and changed her appearance without much thought and resistance. I wouldn't say that's how it is in my experience, but let's say Akko has very convincing charming techniques... which she doesn't, from her perspective, she seems just as introspective as Mari in her volumes. So in the end both feel homogenized cute girls, with Mari being the quieter of the two in conversation, until we switch to Akko's shoes and have the same deal...
The way Akko dragged Mari into her materialistic world and Mari quickly embracing it doesn't feel natural. Mostly because there's absolutely no counterbalance, it's a Slice of Life about materialistic girls, not taking an introvert out of their shell. And Mari herself didn't offer anything of her own unique character and volition to Akko's life, aside from her obsessive, sudden love for her. Sure, that's something, but I mean something from herself before she was a part of the story, like literature. It can't be too hard to share a few metaphors, interesting outlooks on life and the materialistic culture. Doesn't have to be commentary, but offer her own twists and character to a situation, instead of just being present and integrated in it without any questions asked.

If I wasn't told that this was a yuri manga, I wouldn't mind my time with it. But with the scarce drama, which equates to a tease really, the sidelined relationship for fluff, and just spinning its wheels for its own sake. I simply regret my time with this manga. It's trite, even boring at times, noisy in presentation at moments, and doesn't offer anything enriching either the mind or the soul in terms of experiencing romantic trials. It doesn't even teach proper make up techniques or shopping tactics, just faffing about.