Running Mutant for 10–20 seconds per subject mechanically answers ~90% of questions a human reviewer would ask (should this be <=, is this equal sign magical, can this method call be removed). Human time is the most precious resource on a project; CI integration in incremental mode is cheap, so mutation testing is a no-brainer for clients who understand that metric. Reviews get faster and higher-quality because mutation testing establishes a lower bound of coverage.