Every THE D[AI]LY BRIEF article on Claude Sonnet 5.5 — enterprise AI analysis, benchmarks, vendor comparisons, and ROI frameworks for technology and business leaders. Updated as new coverage publishes.
On a 30-turn agent loop, prompt caching saves 80-89% depending on the provider, not 90%. A timestamp in the system prompt drops Claude's saving to 6%, and a volatile tool definition makes caching cost more than not caching.
October 1, 2026 · 17 min read
Prompt caching cuts a 400K-token long-context answer to $0.085 on Claude Sonnet 5.5, but RAG still answers for $0.017. The crossover formula, the accuracy-at-depth evidence and the latency users notice.
October 1, 2026 · 14 min read
Gemini 4 Argon tops the Vals Index at $15.68 per test, cheaper than Claude Sonnet 5.5 and Opus 5.5 even at its $4/$20 standard price. But access is limited to Fairwind security teams and trusted testers, with no GA date.
September 30, 2026 · 7 min read
Claude Sonnet 5.5 lists at half Opus 5.5's token price, but Artificial Analysis measured it at $7.60 per task at max effort against $3.46 for Opus at xhigh for the same score. It saves money only at low and high effort, and five breaking changes sit behind the model-ID swap.
September 28, 2026 · 10 min read