Finished Wool last week
As I mentioned before, I wasn't able to borrow Wool before reading Shift. Now I have also read Wool, I prefer the order I had to follow. I liked having the background knowledge as I'm the type who would have been frustrated throughout the whole first book, wondering why the people are in the silo. Wool follows Juliette's life as she progresses from a highly-valued Mechanic to Sherrif, to outcast. She manages to survive her sentence to go outside the silo and Clean the sensors which provide the inhabitants with their only view of the world outside. What happens after she leaves the silo kept me reading way past my bedtime.