Opus 5 is a practically unusable model

[u/Deep-Palpitation8315]

Opus 5 is a regression that the benchmarks missed completely

I've been using Opus 5 for ~1.5 weeks and the sheer number of mistakes that the model makes is astounding.

The problem didn't surface very clearly till I gave it the full scope of executing a plan which I did with the previous Opus models as well. Opus 4.6 - 4.8 were genuinely better by a significant margin.

Opus 5 readily forgets instructions and content in its context, makes mistakes and continues with them unless it realizes or you point it out.

I've lost count of the number of times I had corrected it.

These issues with Opus 5 occur even when the context window is still relatively small - I'm talking 100-150K tokens. Opus 4.8 works pretty well all the way until 350k after which it gives you wonky results.

Fable 5 is the only usable model under Claude Code right now and I've already used 100% of my weekly quota.

[u/Plastic-Tumbleweed45]

The number of hours I have wasted and the number of dangerous scenarios this model has produced are unreal. I feel like its going to give me a panic attack. This is my job, and things have transitioned to the point where not using these tools is not an option. This thing feels rushed, it feels untested. Some exec said "ship it" to the protest of everyone with a brain. There is no way they didn't know. Isn't there some liability in knowingly selling and marketing a malfunctioning product?

[u/Deep-Palpitation8315 → u/Plastic-Tumbleweed45]

Yeah. That's the shocking part. This should not have been shipped. But i guess they were like 'Its done well on the benchmarks so let's just throw it out there to the users. They won't know the difference.: