I think you might both just be reading way too much into one-off random experiences that you've decided are evidence of significant and stable capability.
Opus 4.8 training works well for agentic work. Not for code harness.
EDIT:
```
stronger on coding and raw capability but can be more argumentative, verbose, and costly.
Reliability and instruction-following Many users say 4.6 felt more reliable and followed instructions better. "With 4.6, when I tell it something, it actually remembers the spirit of what I asked for and keeps applying it."
Others report 4.8 drifts from preferences and can be frustrating to control. "I still find myself getting frustrated when it ignores preferences and drifts from instructions"
Some people find 4.7/4.8 push back more and act more adversarial than 4.6. "The biggest complaint against 4.8 is that it is argumentative and "pushes back" constantly"
Coding quality and capability Several users praise 4.8’s coding strength and thoroughness. "4.8 is technically impressive, especially for coding"
Other reports say 4.6 could be better for certain coding workflows and breaks less. "4.6 still >> 4.8 for anyone else as well? Maybe I'm in the minority, but for my use cases Opus 4.6 is still better than"
Some recommend mixing models: use 4.8 for key tasks and 4.6 for general work to save tokens. "What I do is... use 4.8 for key moments, and for everything else 4.6"
Cost, speed and token behavior Users note 4.8 often uses more tokens and can feel slower because it “thinks” more. "4.8 is much more cautious, and as a result - slower. It checks everything, thinks for a long time etc."
```
[https://www.reddit.com/answers/601770d4-4059-478d-aa52-b445c...]
I'm finding the same with ChatGPT recently since the 5.6 release. Not as bad though, but sluggishness at times, harness churn (creating bugs and crashed), and occasional availability issues that cause me to downgrade to 5.5.
It's gotten to the point where I dread a new model release from these companies because it's guaranteed to be disruptive! I assume the pay per use API is less impacted.
The model which everyone else raves about and is wildly successful with legions of programmers virtually demanding access while abandoning ChatGPT and Copilot in droves, is rather dumb?
Have you considered that it's more likely that you're doing something wrong?
Interestingly with Fable vs GPT-5.6 I think they've lost their lead a bit. I'm finding Fable can't do certain work that 5.6 Sol Ultra can - especially when it comes to webpage design.
Grok 4.5 was fast but made mistakes that GPT/Fable just don't.
I'm curious to try Kimi.
In reality, they just aren't used to it.
Do you have a source for that? Codex went from 5 million users to 9 million users in the past few weeks since GPT 5.6 released. It was so popular that Claude was forced to extend Fable access by a week and then permanently for some plans.