It's popular not to like Coppola after Apocalypse Now. Everyone claiming that the Godfather trilogy and Apocalypse Now are brilliant, yet everything else is "An example of an egomaniac not having objectivity." I've read a lot of reviews and this is all that I've read as the complaints for his later stuff. Sure the negative reviews focus on how thin the characters are thin, and the plot covers a short span of time. But honestly it's a Fairy Tale, and fairy tales have simple plots and thin characters. These same people would praise films like the Princes Bride, or Beauty & the Beast, but not One From the Heart. And why?
Because One From the heart has amazing music, from Tom Waits that almost makes it worth seeing just for that. The movie is a musical, which is gutsy for anyone to write a new musical, but the lighting technical achievement is incredible. The film has what I would call "Color Scenes," where each scene is lighted heavily with certain colors, which play into the emotion of the scene.
The film is an amazing achievement, for the visuals and the music, which is what it sought after to achieve. Ignore the negative reviews about what a disappointment it is, because the people who write those reviews don't have their own opinion, it's nothing but people repeating the Coppola myth of losing his touch. All he lost was the studio support. And because he focuses on perfecting his art and not making millions of dollars.
Great Film, go see it, if you like good movies and don't get doped by the fake critics who talk from a lens that says "this movie is suppose to be bad."