Sonnet 5.5 tops the Coding Agent Index at max effort, while xhigh offers an attractive cost-performance trade-off: 63 points versus 68 for less than a quarter of the cost

In Claude Code, @AnthropicAI’s Sonnet 5.5 scores 68 at max versus 63 at xhigh. At $14.19 versus $3.33 per task, choosing xhigh cuts cost by 77% for 5.5 fewer Index points.

Max generates 4.8× as many output tokens and takes 3.4× as many turns. It improves all three benchmark scores, with the largest gain on Terminal-Bench 4.0: 58.1% → 66.2%.