Anthropic's Duet, a personal-assistant harness powered by Opus 5.5, distinguishes itself through speed, organizational hierarchy, and restrictive access controls. The author reports Duet prioritizes snappy responses over background processing, outperforming other Claude UIs using the same model. Its channel system automatically manages session hierarchy, allowing rapid switching via Cmd-k and cross-referencing between workstreams to prevent context loss. Access policies enforce per-channel GitHub repository restrictions without storing credentials; Duet leverages Claude's existing connector ecosystem rather than requesting keys, a notable departure from competitors like Muse. Responses are concise by default, utilizing emoji reactions for acknowledgment instead of verbose elaboration. The architecture implements a tiered hierarchy: a top-level bird's-eye view with no low-level access, channels with constrained context and specific repo access, and sub-threads operating in isolated code sandboxes. Local host access via the desktop app is limited to QA and deployment stages. Despite beta glitches—including invisible running threads and race conditions in delegated repo attachment—the author finds Duet replaces most AI workflows by codifying a preferred agent-management hierarchy into the core product, though Dot remains superior for voice interaction.