I was waiting for someone else to start, because I don't feel like I have that much to say.
I find the story of the journey to Valinor a bit tedious, with all the splits between the different groups of Elves and their assorted names. It feels like an exam is coming at the end. Also, I feel more sympathetic than I perhaps should towards all the more chaotic subgroups of Elves who kept pausing whenever they saw something pretty, or wandering off, and forming subgroups which were later given less flattering names.
BTW, I used to wonder why Ingwë, Finwë and Elwë were chosen as the ambassadors, and how they relate to the original Elves who awoke (who were already divided into the three kindred we see later, and had a different, named, set of leaders). Well, the new Tolkien book (Nature of Middle-earth) says they were all 6th generation Elves, descended from the original leaders, and chosen for their personalities.
I really do like the part about Varda kindling the stars, both because it is very nice imagery, and because I like how Mandos says "we can't give the Elves any proper light sources, only the stars" and she reacts with "well, if they're to have only stars, I will make sure those stars are awesome".
I also like Melkor's propaganda campaign against Orome. Very clever.
The thing about how the Orcs are descendants of corrupted Elves is horrifying, but also spiritually confusing, and contradicted in other sources. See, for example:
https://en.wikipedia.org/wiki/Orc#In-fiction_origins