Measure your own productivity instead of trusting how fast you feel

Feeling faster and being faster are different. In METR's randomised study published in July 2025, 16 experienced open-source developers worked on 246 real issues from their own projects, with and without early-2025 AI tools. They took 19% longer with AI allowed, yet beforehand expected a 24% speed-up and afterwards still believed AI had made them about 20% faster.

METR's February 2026 update, with a larger group and newer tools, points toward a speed-up, but METR calls it very weak evidence because of how hard the newer setup was to measure. DORA 2025, by contrast, reports that over 80% of respondents say AI has enhanced their productivity.

These results do not contradict each other as much as they look: self-reports and controlled measurements answer different questions. For your own career, the lesson is to measure. Time a few real tasks with and without AI, note where it helps and where it costs you, and decide from evidence.