Claude Code is the best and only harness you need right now... i don't think it wins in terms of pure performance and efficiency (at least for coding), but it's genuinely awesome to work and orchestrate other harnesses and models i have GPT-5.6 Sol and now Kimi K3 running inside it, they both perform better than in their proprietary harnesses running all of it inside a light ADE with simple orchestration skills for calling Codex for browser/computer use and image gen