Using Claude Opus 5.5 as your daily driver for knowledge work

Anthropic says Claude Opus 5.5 is now the default model on Pro, Max, Ultra, and Team plans and recommends it for daily knowledge work such as research, analysis, and producing memos, reports, spreadsheets, and decks, priced at $4/$20 per million input/output tokens. The post describes internal tests on research reports and a fictional merger analysis, plus guidance to start at Medium effort, drop "think hard" prompts, and attach charts rather than retyping them. It also walks through a demo project where Opus 5.5 tested four theories for slowing retail growth and proposed an alternative explanation involving new stores opening too close to existing ones.