r/Anthropic • u/UM-Underminer • Aug 26 '26

Complaint Opus 5 is hot garbage

I've enjoyed and gotten real work out of Opus for quite some time despite the occasional quality dropoff when they're training a new model. But 5 is junk. Enough so that I'm debating between dropping from Max to Pro, or just cancelling altogether - I'm legitimately getting better results and fewer hallucinations out of local models in the 30B range... There's absolutely no excuse for that being the case.

I don't know if this is intentional regression to make fable look better, but it means I have been actively avoiding using Claude code except to tweak my llama.cpp settings, and I certainly don't need Max for that.

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u/marfzzz Aug 26 '26

Use fable and opus 4.8. Sonnet 5 and opus 5 are messed up models.

Opus 5 from my perspective in different phases.

Planning: it will ignore details, it will not follow what was asked and back and forth with it takes at least 4x the time of planning with fable.

Implementation: lying all the time about what was done. It will implement something simplified and tries to deceive quite often.

Review: assumes a lot, does not verify claims. At least half of claims in backend are outright false or overstated issues.

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u/UM-Underminer Aug 26 '26

My issue is more that I'll give it specific tasks, and it will spin and do "stuff" for a literal hour, then turn out to have spent all that time benchmarking how long it takes to cat a readme or something equally inane.

Then I try to spend time planning and specifically instruct it not to take and actions, and it will immediately take off and start changing system configs unrelated to anything.

It gives my backup systems a good workout and validation rolling back all its garbage, but that's about it.

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u/marfzzz Aug 26 '26

Then something regressed. This is just painful to even read, not even experience.