The most important thing about Claude Sonnet 5 isn't the benchmarks. It's what happens when a Sonnet-tier model matches Opus performance at half the cost. Opus 4.5 scores 80.9% on SWE-Bench. Sonnet 5 reportedly clears that same mark. With a 1M token context window. At Sonnet pricing. For vibe coders running Claude Code 8 hours a day, this isn't an upgrade. It's a cost revolution. The model you use all day just got twice as affordable and potentially faster.