Claude Haiku 4.5: When to Use It Over Sonnet 4.6

When Anthropic released Claude Haiku 4.5 in October 2025, the usual reaction was "nice, a cheaper model." That framing misses what matters. Haiku 4.5 scores 73.3% on SWE-bench Verified — inside the range of models that cost three times more — and it'...