1. INTRODUCTION  
2. SAMPLE & OBSERVATIONS  
2.1. X-ray (Chandra)  
2.2. Spectroscopy  
2.3. Radio  
3. REDSHIFT DEPENDENCE OF THE ENTROPY THRESHOLD FOR MULTIPHASE COOLING  
3.1. Has the Entropy Threshold Changed With Time?  
3.2. Comparison to McDonald et al. (2016)  
4. REDSHIFT DEPENDENCE OF THE ENTROPY THRESHOLD FOR AGN FEEDBACK  
4.1. A Disappearing Dichotomy  
4.2. A Lack of Extremely Luminous Radio Galaxies in SPT Clusters  
5. SUMMARY & FUTURE WORK