As one of the producers said in the behind-the-scenes material, it is a biopic that is not a biopic, and a musical that is not a musical. It starts out with Elton in rehab, relating events from his life at a group meeting. Then we see the events play out in flashbacks that every so often break out in musical numbers. The songs used in the movie (mostly his songs from the 1970s) were selected from Elton's vast catalog of music but were not exactly tied to the time frame in which the events in his life actually occurred. For example, the movie shows the song Saturday Night's All Right for Fighting being played before Elton and Taupin ever meet. The songs were used mostly to fit with particular scenes in the story, not to convey when in his career they were actually released. Also, the movie does not tell events exactly as they happened or when they happened. For example, the final act of the movie shows Elton leaving rehab using the song I'm Still Standing which was released in 1983, yet he actually went to rehab in 1990. Even though the movie is a more "fantasy" telling of Elton's life, using actual events but oftentimes putting a different spin on them, it does convey the mess his life was as he was coming to terms with his sexuality, using and abusing drugs and alcohol, and his issues with food, as well as his rather horrible family. Bryce Dallas Howard does a wonderful job playing Elton's mother and certainly gives the impression that she saw him just as a meal ticket.
The 4k set is a two-disc set containing a UHD disc and a regular Blu-Ray disc. The movie looks and sounds great in the UHD format. The UHD disc only has the movie, and all the extras are on the regular Blu-Ray disc. Those include about 20 minutes of deleted scenes, a handful of making-of featurettes, a version of the movie that will display the song lyrics during the musical numbers, and a version of the movie that just plays the musical numbers. All-in-all a very good amount of bonus material for those who like to watch it.
Overall, the movie is very good. While I do think it would have worked as a more "traditional" biopic, without having musical numbers where everyone in the scene breaks out into song, I get why the choice was made to do it that way. Taron Egerton not only does a great acting job playing Elton, but he also sang all the songs, and not just lip-synching to the real songs. This allowed them to re-arrange the songs to help tell the story yet still keep the character of the original songs. For many of the songs, they were arranged to start differently and then transition to sound more like the album versions. While I cannot say that the movie is going to appeal to everyone, if you are a fan of Elton John's music and/or know a bit about his life, it is definitely worth checking out.