I've been playing with this model a fair amount over the last 24 hours, and I can confirm it's quite capable, while being a little bit verbose (I've seen it reconsider things 3-4 times in thinking traces before deciding on a path forward), and not being quite as good as GPT5.5 at working through complex abstract requirements.
Honestly it's good enough that I feel comfortable recommending a Z.AI sub + a $20/mo OpenAI sub for all but the most AI pilled multi-orchestrators, or the die hard Claude fans. GLM writing + GPT reviewing/debugging feels pretty unlimited and minimally worse than just doing everything in GPT with the $200/mo plan.
> while being a little bit verbose
Discovered today that they set reasoning effort to max by default. So that’s probably why
> GLM writing
This is honestly what I care bout the most now, which is how well they can write. I think we have reached a point now, if you know how to program, you can provide enough information for the models to pretty much do what you need.
What they still struggle immensely with is the writing which has too many nuances but they are truly getting better.
This is my workflow. And then once a day I copy paste the code into the free Claude Sonnet so it comes out actually readable.
After having got a taste of Fable 5 for me Opus 4.8 doesn't cut it any more -- and I don't know how to put this, I don't know if it's just me, but it's rhetorical flourishes are starting to really grate on me, never mind that it is at times deliberately weasel-wordy and economical with the truth until pressed. Opus 4.8 is definitely a stronger coding agent than DeepSeek 4.0 or Kimi 2.7 succeeding where they flounder and fail but its way of expressing itself conversationally is making me reconsider my subscription …
You are not alone. How about GPT 5.5? Does it come close to Fable 5?
GPT 5.5 xhigh is smarter than Fable but Fable like Opus 4.8 as well is faster and seems more “agentic”. It’s easy to test this. Build a fairly complex software with Claude(opus or Fable).
Review the commits with both Claude and GPT 5.5 Xhigh. You can see that Fable is still sloppy(er) compared to GPT. You can test it the other way around as well(drive the dev with GPT and review with GPT and Claude). You get the same result Claude has an edge though and that’s on building more beautiful user interfaces.
5.5 is pretty good. It's no Fable though. It is definitely better than opus tho.