In the informational book carousel, everyone finds at least a few interesting books even though most of my students don't like to read, don't want to read, and/or don't think reading is cool. A variety of books is critical to holding student interest in the lesson itself, which is usually a reading and/or writing skill practice. It also exposes students to the Big Wide World of Life that's typically more than they see in their own life and in the social media they choose to ingest. Additional benefits: physical activity for students, quiet classroom for teacher sanity.
Two main carousel complications:
1. Set-up of materials takes time and effort, but the payoff of solid planning is excellent. Invest in authentic reading material, and keep the paper/writing materials simple. I usually write my own questions, based on the goals for student learning and student needs. If I don't have stellar school library resources, I would borrow public library books since I can monitor student use closely.
2. Managing the flow of students through stations requires constant vigilance. I try to vary the the questions based on learning goals/needs, but there will always be some students who work quickly and some slowly.
Say what we will about the ills of high-stakes standardized tests, but the vast majority of students who score below grade-level proficiency and have to take my class are not strong readers, meaning (to me) they don't read deeply or widely. A small minority may enjoy reading a narrow range of genres or topics ("Do you have any more Wimpy Kid books? The Hunger Games? Football or hockey?), and they tend to read for chuckles and thrills. Both are authentic reader experiences, but neither wide nor deep reading.
How wide or deep should students be reading? I'm not sure that's the right question, considering generally low to mediocre expectations of academic character in American society. Let's focus on excellent academic character, emphasize the value of struggling through challenges with hard work and determination to realize long-term goals. Sometimes working harder is smarter - apply Malcolm Gladwell's 10,000 hour "outliers" rule.
As for the use of standardized tests to scapegoat educators and bankrupt public education, I bet the enterprising folks pocketing insane millions of tax dollars (Pearson, I'm talking about you and your buddies) are happy with their 10,000 hour investment in the study and practice of making money. How wide and how deep is your love of money compared to your love of public education?