Not sure how to answer that, but sure, I can imagine plenty of ways in which a local repo could be screwed up that might require a strip or just a complete fres

Not sure how to answer that, but sure, I can imagine plenty of ways in which a local repo could be screwed up that might require a strip or just a complete fresh pull. "All breakage cases" is pretty broad. My personal reasons for liking mercurial is some pretty amazing tooling (hg absorb, hg fa --deleted, revsets/filesets) combined with a friendly commandline with fairly sensible defaults.