OpenCode is a quirky, buggy mess in my experience, but Pi is pretty solid and I’m glad to have recently switched over. Zerostack looks promising for certain types of users too.

Mimocode from Xiaomi is a fork of opencode with some improvements.

There is also reasonix, which specializes in good caching tlto keep costs low;

https://reasonix.io/

I agree opencode can be a bit buggy, but codex and claude code are not much better either.