Most model comparisons I read have the same flaw: the models never touch the same problem under the same conditions. One gets a carefully groomed prompt, the other gets a sloppy one. One runs against a clean checkout, the other inherits half-finished edits from the previous attempt. The conclusion tells you more about the harness than the models. I wanted a comparison I could actually trust for my codebase, so I built a small bake-off harness around git worktree . It runs two coding models...