You are exactly right. The goal here isn't to optimally describe the entire distribution but to improve the end-user experience for higher-than-tolerable respon

You are exactly right. The goal here isn't to optimally describe the entire distribution but to improve the end-user experience for higher-than-tolerable response times. The difference between 80ms and 100ms isn't noticeable. Between 100ms and 1000ms it certainly is.