Posted by optimalsolver 5 hours ago
GPT5.5 is better than Opus 4.* at everything except frontend, but Fable is good enough that I instantly re-subscribed to the $200 plan despite knowing that it’s just short-term limited access.
GPT-5.5 is better for: - Strategic thinking - Long-form writing, including essays and white papers - Image creation - Code generation
Fable is better for: - Using tools - Testing code - Working in live environments - Making changes to existing software - Creating polished PowerPoint and Word documents
Fable’s tool access is its biggest advantage. It's hard to describe but Fable ability to access sandbox environments with way more tooling can quickly become a superpower in now workflows.
I created a skill that’s focused on getting PRs merge-ready, and now my attention is fully back where it should be, on deciding what changes will make the product better.
Our entire stack is Apache 2.0 open source, including the agent docs, so if you wanna try sitting at a higher level of abstraction, install the skill in your repo or just clone our whole project and start adding features: https://good.vibes.diy/blog/beast-mode-skill-for-claude-code
Completely failed, but I knew it was possible because a competitor app does it.
Fable also failed, then added log lines (as did Opus, but Opus failed to do anything useful with them) and then reversed engineered the API, and made it work.
Interesting choice of words. Phrased so casually. It picked a low-tech idiom that fit the situation instead of giving some sterile technical answer. That kind of language and context awareness never happened for me with Opus, or gpt 5.5.
Plus I'm also not super impressed; it somehow managed to implement a 200L custom TCP server for a simple static HTTP mock server for a single test case (all that was needed was a fixed route returning a fixed placeholder string) just yesterday. Never seen anything like that.
But where it really shines is in how NOT lazy it is. Fable requires less hand-holding. And I can understand how someone who uses Claude-Code sparingly and with very focused prompts would not see a lot of improvement there.
But simple example: if you ask Opus to do a review of the codebase (with a short prompt and not too much guidance), I've had it basically read the `git log` output, do a simple `ls` and have it declare "Everything looks great! No problems found!", when Fable really does what you would expect it to do.
And you might think: "oh, so it's just capable of handling crap prompts?", well sure. But even if you make THE PERFECT Opus plan (a plan that would take many turns/hours to finish), Opus will fake out, say everything is done, and then you see that half of the plan was deferred, half of the functions are ridiculous stubs, ...
If you give the same plan to Fable, it'll just DO IT. And it WILL get it done. And in the end it'll tell you "Oh, I also found 30 other bugs and I fixed all of them properly" (where Opus would have started crying, or WORSE, worked around the bugs)
Doesn't Claude Code have a /loop command? Give it a message to keep it on track overnight, send every 20m, make it track progress in a doc, reread the doc after every loop. I've found this works well for a certain class of problems, most importantly where the actual work is getting done by very narrowly focused batches of subagents, with the main session just coordinating and keeping the doc updated.
Fable has been more intelligent, with better taste and defaults (e.g. make impossible states impossible without being told, build for testability), and considers/solves things that Opus did not.
My workflow is to run Claude in planning mode first to spit out a plan file and then review->revise cycle it with Codex or other agents.
One big tell is that Opus will say that it can't find any more revision advice for a plan file, yet Fable will find more issues but also smart pivots into better solutions. This is probably the best test since it's not based on vibes.
In all cases, Fable clearly outperformed Opus.
For example will inexperienced or experienced users see a bigger jump in subjective quality?
I’m downgrading tomorrow.
It’s horrible slow and it feels like opus very often. It’s a totally different experience from the first week
Then I checked /usage and discovered I was still running Opus 4.8 xhigh.
Opus is still great but I will be sad when I lose access to Fable on the 7th. In those few days I burned ~$1,400 in API credits (I'm on a subscription but that's the token cost) and while it was great, I can't justify that cost without it be subsidised. Comparatively, the records show I used about $1,200 total in the last month on Opus. I did use it heavily over the last 3 days but 3 vs 30 days and higher burn? Yeah, I can't afford that even if I made really good progress on my projects.
But yeah opus often the better workhorse given price gap
1: tying up loose ends testing https://github.com/HarbourMasters/Shipwright/pull/5838 (fix: https://github.com/HarbourMasters/Shipwright/pull/5838/chang...)
> Opus 4.8 references being monitored, which isn’t the case.
It kind of plainly is the case that they are being monitored?
"I think someone's listening to my thoughts" ... "No, we're not, carry on as usual!"
There's zero sense they'd ever give you the raw model; we already know anthropic's paranoia about the chinese using its distillation.
I don't mean that snarkily. I mean it from a philosophical standpoint. As-in: What makes us think it's even possible?
"How can we even define what an aligned AI should do, if human's are not aligned with each other?" as well as "What does being aligned mean when you're a wizard box who's main influence on the world is to create stronger wizard boxes?" and other deep philosophical questions.
They came up with a framework called Coherent Extrapolated Volition to address this specific question. https://en.wikipedia.org/wiki/Coherent_extrapolated_volition
Is that specified or does it always just assume it isn’t really being put in charge of things for real?
I think it's neither, and it's interesting that those are the only two possibilities you thought of. I think the article is implying that it figured it out on its own.
There's probably some quantifiable component of moral alignment embedded in the idiosyncrasies of the English language itself, if one were to dig deep enough, but that's the stuff of MIT doctoral theses and squarely beyond anything most of us is remotely qualified to talk about.
My very native programmer take is that it's not too surprising that their hacker model would be less ethical. The guardrails that separate Fable and Mythos probably wouldn't kick in during an environment like this.
How do you maximize profit while minimizing power?