> It seems to really be a nice step-up and is getting quite close to the frontier.

IMHO it's already surpassed them. I vastly prefer my personal GLM and OpenCode setup to the Claude Code and Opus one that I have to use at work. The former makes way fewer StackOverflow brogrammer-tier mistakes and is considerably better at following instructions. The harness UX is also vastly superior as it doesn't ignore, randomly change, or incorrectly report settings.

Maybe it's the harness and I'd have even greater success with OpenCode and Anthropic, but I think it safe to say that Anthropic's moat is evaporating.