I don't know why, but I actually found Dust kind of forgettable.
It's the third in the phenomenally successful Wool trilogy, featuring the excellent Wool, the quite-good Shift, and now the OK Dust. After the flashback fun of Shift, Dust returns to the "present" of Wool, the "present" of Silo Eighteen, with Juliette installed as mayor and Lukas as head of IT (boo). Juliette has cooked up a crackpot plan to rescue Solo and the kids from Seventeen, people in Eighteen are grumbling about this, Juliette and Lukas are arguing, and bad stuff is going down in One, as per usual.
I think a major problem with Dust, for me, was the lack of the stellar character development that made Wool so gripping. Dust is simply too short to sustain such development: there's a lot of action packed into its 401 pages (there needs to be, to tie up all the loose ends) and not a lot of, you know, emotion. I definitely felt, for instance, that Lukas got a little dropped by the wayside: he dies, actually dies, and no-one really seems to notice, especially not Juliette, his actual lover. (I liked Lukas. Can you tell?)
That's it, I think. Dust was, like its name, rather dry and emotionless. I didn't feel Juliette's quandraries, Charlotte's fear, Lukas' agony. I was watching a news report, not reading a story; I saw all the facts, and how they fitted together, but I didn't experience the epiphany.