Just finished seeing this (finally!) and that blew away my expectations, expectations which weren't exactly low going in (both from the reaction to it and from Whiplash). Musicals generally aren't my thing (although I do love Les Miserables, Sound of Music, Wizard of Oz, and Willie Wonka and the Chocolate factory), so I was somewhat hesitant, but thankfully that was not necessary.
I wasn't a huge fan of City of Stars, but aside from that I felt the music worked really well, and the movie felt like a throwback to films of bygone days with a modern edge which just worked fantastically well together. There were some moments which, on their own, are somewhat sketchy, but the film was definitely more than just the sum of its parts.
The opening, the dinner scene mentioned above, the planetarium sequence, and the ending, were particular stand-out sequences for me; EDIT: I also loved the final audition. I can't wait to go and see it again.