After having used GLM 5.2 and Opus 4.8 for enough time, I'm very unconvinced of the benchmark maxxing claims - if anything, GLM 5.2's rather lackluster performance on benchmarks compared to Opus 4.8 paints the opposite picture when compared to the subjective experience.

When I first used Opus 4.8, I threw several different workloads I had at it - I have Claude doing a lot of misc projects whose primary purpose is pretty much just studying what AI agents can do for my own curiosity and no other reason. Opus 4.8 was one of the first models I ever snuck in there that basically ran out of control. No previous Opus or Sonnet model I had used ever did this. Within hours every agent I had running was writing non-sense tool calls that echoed pretend commands that didn't exist, like 10 in a row, and talking about the "tool channel" being dirty. I switched back to Opus 4.7 and assumed Opus 4.8 was legitimately just broken.

I did come back to Opus 4.8 and found that it was indeed, pretty powerful. But that initial experience has stuck with me on just how narrow of a perspective any given test or benchmark is guaranteed to have. LLMs are too broad, it really doesn't matter what you try to do in your benchmark, you will necessarily get a limited view of what the model is capable of and its shortcomings. This will remain true for at least as long as models are susceptible to massive swings in performance based on randomness and minor differences in prompts and other environmental factors.

I'm not saying benchmarks are useless or that your benchmarks are not possibly closer to the truth either. All evidence at least points to the idea that Chinese models perform very well in coding but often have more mixed results on other tasks. I'm just saying that at this point, benchmarks feel like they have limited connection to my actual real experiences. GLM 5.2 actually scored kinda meh on a lot of benchmarks (compared to closed frontier models) but my actual experience using it does not match this.

And I'm definitely not saying GLM 5.2 is better than the frontier LLMs here, just that the race is close. I still prefer GPT 5.5 right now for code review, I think, and Opus clearly has some advantages depending on the task. It's just no longer a given that Opus 4.8 will perform better than GLM 5.2 on any given task, so to me the calculus behind "using the best model available" is getting complex and you might need to get a feel for what models have what strengths to really figure it out.

I do feel like the "use the best model available" mentality is not going to die any time soon, but if it does die, it will be gradual and start soon for programming. Modern LLMs are still not a full superset of what human programmers can do, but still larger models are definitely starting to hit diminishing returns for tasks at the lower end of complexity, and that is a big deal. It's a weird world where some tasks you can feel kinda confident just throwing Gemma 4 at it and not sweating whether you should use a better model; I've certainly done it for some quick Python scripts or getting an overview of some code I'm unfamiliar with.

GLM 5.2 beats Claude in our benchmarks