TL;DR: Pleasant, lighthearted fare with hints of romantic friendship. Great for slice-of-life, comedy, and shoujo-ai readers!
I love Fujieda Miyabi's works. They are very easygoing works that are great entry-level reads for the slice-of-life and shoujo-ai genres. "Alice Quartet Obbligato" does not stray from this, although it has a much heavier focus on slice-of-life and character. That said, it still has hints and traces of romance for the girls' love reader to enjoy.
Story: Consistent with Fujieda's works, this manga has a very simple premise that acts more like a backdrop than an actual story. Four girls work to design and make clothes in the clothier shop
Alice Quartet, and they talk and interact with each other as they work. There is a lot of comedy in this manga, and there is a very lighthearted and easygoing tone throughout the work. The romance comes in the latter chapters, and it does feel a little rushed - thankfully, that is far from the main focus of this work.
Art: Pretty, graceful, fancy. These girls not only make fashion, but have great fashion sense - great character and costume designs all around, critical for a manga about clothes. Clear lines in the drawing further emphasize the elegance Fujieda bestowed on his characters. Most of the panels have simple or no background, focusing instead on the characters and dialogue.
Character: Nothing unique, and all of them more or less fall into some sort of archetype. Fumi is quiet and hardworking; Suika is vibrant and enthusiastic. That said, the interactions work very well and they play off with each other smoothly in every chapter.
Enjoyment: Very pleasant, very lighthearted fare. Think of it as a snack - it's a short manga that can be read in one or two sittings, and works effectively as a breather between more serious or longer works. It's very accessible for people new to slice-of-life, comedy, or shoujo-ai, and I recommend it as one of your first reads!
Overall: I really enjoyed this manga, although it isn't particularly unforgettable or striking. If you're looking for something to tide you over or for a short change of pace, I highly recommend giving this an hour or two of your time.