The difference is in scaling. The top US labs have oom more compute available than chinese labs. The difference in general tasks is obvious once you use them. It used to be said that open models are ~6mo behind SotA a year go, but with the new RL paradigm, I'd say the gap is growing. With less compute they have to focus on narrow tasks, resort to poor man's distillation and that leads to models that show benchmaxxing behavior.

That being said, this model is MIT licensed, so it's a net benefit regardless of being benchmaxxed or not.

They do. Pretty much all agentic models call linting, compiling and testing tools as part of their flow.