GLM 5.1 is pretty good, probably the best non-US agentic coding model currently available. But both GLM 5.0 and 5.1 have had issues with availability and performance that makes them frustrating to use. Recently GLM 5.1 was also outputting garbage thinking traces for me, but that appears to be fixed now.
Use them via DeepInfra instead of z.ai. No reliability issues.
https://deepinfra.com/zai-org/GLM-5.1
Looks like fp4 quantization now though? Last week was showing fp8. Hm..