This book took me a few times to finally gather enough momentum to get to the parts that made it impossible to put down.
Just amazing. The perspectives and the concepts and the characters are all delightful. The world is unique and powerful, especially with a great deal of care being placed on linguistics, which was super cool. Don't stress about not understanding the world, as it will come at you pretty quickly. There are a great deal of strange words and concepts that will finally catch up (IE - Esk, or One Esk - spoiler a Justice is a troop carrier ship, each deck of the ship is a 'decade' kind of like a military company, and each one has corresponding Ancillaries - So One Esk is just the primary Ancillary of the Esk deck). Other words are similarly different decks of these ships.
Don't worry, you will catch on, and I hope you do. It's a fantastic ride. I can't wait to finish the rest of the series.