A UK government trial of Microsoft's M365 Copilot involving 1,000 licenses revealed mixed results regarding productivity. Users reported high satisfaction, with 72 percent expressing satisfaction or very satisfaction with the AI assistant. Tasks like summarizing meetings and writing emails were particularly well-received, with users finding these actions quicker and of higher quality compared to non-users. However, the overall productivity gains were less clear than anticipated. The tool actually slowed down more complex tasks such as Excel data analysis and PowerPoint creation, often resulting in lower quality output. Corrective action was frequently needed for AI-generated content in these areas. While some participants felt it freed them for more strategic work, the trial ultimately found no definitive overall productivity increase. Usage varied, with Word, Teams, and Outlook being the most utilized applications. Despite user enthusiasm, the cost-benefit analysis for M365 Copilot remains a consideration for Microsoft.