@danshipper: BREAKING: Claude Opus 5 is OUT NOW! And…it’s a hard model to love. We’ve spent the last week @every testing it across c…

BREAKING: Claude Opus 5 is OUT NOW!

And…it’s a hard model to love.

We’ve spent the last week @every testing it across coding, writing, knowledge work, and our internal agent.

It argued with instructions, stopped before the work was finished, and generally didn’t play well with our existing skills and plugins like Compound Engineering. Our first reaction was: What have they done to my boy?

Then we deleted our existing skills and started from scratch.

Without the elaborate workflows we had built for earlier models, Opus 5 got dramatically better, and even showed flashes of brilliance.

Here’s our Day 0 vibe check:

• It’s a poor man’s Fable. It has many of Fable’s personality quirks without Fable’s genius.
• It breaks backward compatibility. If you’re using it with existing skills and workflows, watch out. It will often stop early or otherwise miss your instructions.
• If you start from scratch, you’ll have better results. @KieranKlaassen figured out that if he just started from scratch without his existing skills, he could get dramatically better results. This is a model that takes some time to rebuild your workflows around—but if you do, there’s a payoff waiting.
• Medium or low effort works better. @KieranKlassenn also found better results using Opus 5 on lower thinking levels. It seems that the more time you give it to think, the more likely it is to do the more annoying behaviors. Don’t just switch to Sonnet for a faster response! Try low thinking.

I have two slots in my workflow:

1. The genius model I use for my biggest hardest tasks, currently Fable.
2. The smart, fast generalist I use for everything else, currently GPT-5.6.

Opus 5 has the personality of the genius, but doesn’t have its top end. So that puts it in a strange middle ground that doesn’t really have a home in my day to day. I think I’ll use it mostly when I run out of Fable tokens.

full vibe check on @every in the next tweet

full vibe check here:

Thanks for the summary @danshipper. I think I be sticking to GPT5.6 for the moment.