A near tie on accuracy (blind A/B by the speaker: 17 vs 13 on the 30 spans that change meaning) and a 6x difference in speed (40 s vs 4m08s for 63.7 min). Different error profiles: pianissimo better on terms and numbers, kb-whisper on everyday words. Aggregate numbers only -- no transcript text or domain terms, this repo is public. Also records the mid-word wrapping bug the comparison found and its fix. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>