Well, yeah, there's not much difference between a histogram and hundreds-of-percentiles. But there's a huge difference between a histogram and just a single per

Well, yeah, there's not much difference between a histogram and hundreds-of-percentiles. But there's a huge difference between a histogram and just a single percentile (whether it's p50, p95, p99, or whatever). If you just want to know _if_ something changed then maybe one percentile is ok (though actually: not great). But if you are trying to figure out _what_ happened (or is happening!), a histogram is really important. Most of the time there are discrete behaviors/factors that are driving performance: timeouts, cache hits/misses, one overloaded host, a canary. The shape of the histogram will help you see those in a way that a single percentile can't.