CLAUDE HAIKU 4.5 WROTE 62% MORE CODE BUT SCORED 16% LOWER THAN SONNET 4.5

Summary from the TLDR Dev newsletter

Anthropic's new Claude Haiku 4.5 model was tested on a WebSocket refactoring task. While it produced the most code compared to other models, its quality was much lower than Claude Sonnet 4.5. Haiku 4.5 over-engineered the solution, prioritizing thoroughness at the expense of code quality, correctness, and maintainability.