Have the length of within-guideline sentences become effectively unreviewable in practice, and is Mr. Nanez-Rivera's sentence near the top of the range for a prison assault -- for which there were mitigating circumstances and that produced minimal injuries as compared to other assaults resulting in bodily injury under the guidelines -- substantively unreasonable?

Have the length of within-guideline sentences become effectively unreviewable in practice, and is Mr. Nanez-Rivera's sentence near the top of the range for a prison assault -- for which there were mitigating circumstances and that produced minimal injuries as compared to other assaults resulting in bodily injury under the guidelines -- substantively unreasonable?