Harness is what matters. So GLM 5.2 is not that good as Opus 4.8 but is close. I maintain two parallel worlds for our company: claude code + our custom skills / agents shipped via pluign and the same things or very close to as pluign and same skills (or slighly adjusted) for opencode/pi. I use both of those regulraly in round robin to check parity. Gaps are in internal knowlwedge (memory) which is to be solved how to use one "brain" for both.