I just did a test project using K2.5 on opencode and, for me, it doesn’t even come close to Claude Code. I was constantly having to wrangle the model to prevent it from spewing out 1000 lines at once and it couldn’t hold the architecture in its head so it would start doing things in inconsistent ways in different parts of the project. What it created would be a real maintenance nightmare.

It’s much better than the previous open models but it’s not yet close.