I used pro via API (DeepSeek API not OpenRouter) with Claude Code, and the planning, visual solution, understanding was fantastic.

I would say I wouldn't notice this wasn't Opus 4.6. What I asked was looking at a feature implemented recently, and how it could be improved. Consumed 3.3 million tokens and create a much better flow.

It had a bug when I started the implementation though related to the API, which I suppose it is something they didn't catch when making their API compatible with CC.