Vs code copilot extension the harness is not great, but Opus 4.5 with Copilot CLI works quite well.

Do they manage context differently or have different system prompts? I would assume a lot of that would be the same between them. I think GH Copilots biggest shortcoming is that they are too token cheap. Aggressively managing context to the detriment of the results. Watching Claude read a 500 line file in 100 line chunks just makes me sad.