I work for Microsoft so I get to/am forced to dogfood all the copilots. GitHub/VS copilot is great. Bing copilot is pretty good. For windows copilot I have no use case.

365 copilot, in my own personal humble opinion, is a steaming pile of garbage, and I think that is why they force it so much (the floating thing in excel, repeatedly pinning to taskbar after I remove it, removing the option to disable it via group policy, an obnoxious copilot box on top of new document, top of every context menu). People don't use it, and the reason people don't use it because it is terrible. It's the only, MSFT or otherwise , copilot that hallucinates its own work - says it made changes but no changes are made. On top of not being able to do much in the first place, especially with the typical tedious tasks like minor changes to many things at once; and mangling spreadsheets when it does do something.