Feeling 20% Faster but Actually 19% Slower: Who Gains and Who Loses with AI Coding?
Three recent studies—an RCT with 16 senior developers, a METR follow‑up, and a large‑scale Cursor analysis—show that AI coding tools can slow experienced engineers by 19% while boosting PR merge rates by 39%, with speed gains depending on task type, code‑base familiarity, and how the AI is used.
