TL;DR for engineering leaders
Pick Claude Enterprise when the workflow is agentic (multi-step tool use, MCP integrations, long context), when audit trail and zero-data-retention matter, and when your team will write code against the API. Pick ChatGPT Teams when the workflow is mostly human-in-the-loop chat, when business users need the UI for productivity, and when you want a managed admin console without engineering work. The shortest answer most enterprises end up with: both, scoped to different jobs.