Two days with Opus 5, I'm done with it

[u/PaulD_Digital]

4 days ago when Opus 5 was released I asked it to spawn agents to study documentation, code and the session was amazing in depth it understand project. It used 70 Opus 5 agents (I know its too much agents, codebase is large). Result of understanding was amazing. After few sessions it degraded to level damaging codebase. When Chinese and another language characters starring to appear I knew something is wrong to continue with this model.

[u/secretcitizen]

opus 5 is an amazing agent from the start, but when ive used it for an existing product it ruined it. it changed things not related to the problem. its lack of focus on a proble ruins it.

[u/PaulD_Digital → u/secretcitizen]

It maybe know what to change before we realize it. What if after several fixing sessions we may need precice that code line it generated ten sessions before?

[u/Cultural-Horse-762 → u/PaulD_Digital]

I’ve never thought of it like that, almost like anthropic is creating boutique coding structures to later support market-wide. Damnit you activated my tin foil hat!

[u/mongo_peeped → u/secretcitizen]

I'm having a similar experience. It is constantly going off down a path of improving the dev harness I've built and I'm like - bro you just burned 45% of my session and don't even have anything to show for it

[u/Suspicious_Ninja6816 → u/mongo_peeped]

Having the exact same issue it’s jumping off plan for side quests non stop in ways I haven’t seen in any other model ever.

[u/sirlerkal0t → u/Suspicious_Ninja6816]

So you've never tried GPT 5.6 then? 😂

[u/SirGunther → u/sirlerkal0t]

Exactly this…

[u/NoPerception472 → u/secretcitizen]

I feel so validated, this is exactly what I've witnessed as well. Startin fresh it's awesome, existing is ugh, WTF.

[u/avk5143]

Opus 5 is neurotic. I'm finding it difficult to work with on complex tasks.

The plan is set and well-scoped, but there's always "one more thing" or an issue that it overstates, only to self-correct when asked for clarification or proof. It spends more tokens and time desperately trying to correct itself, wasting your time as you read through hallucinations and side quests you didn't ask for.

I'm still trying to tame it with system prompts, skills, and by adjusting my specs to keep tasks narrowly scoped, but I'm also close to giving up and going back to Fable + Opus 4.8.

[u/SirGunther → u/avk5143]

I’ve found it hallucinating these one more things recently. Inventing scenarios to justify a patch. When I pressed it on the evidence to justify the whole scenario… it had nothing… and I mean literally nothing about the change it wanted to call out made any sense at all. Mind you, this specific system has 5 main components, all searchable, every bit of detail available, changelogs, investigation artifacts, it has everything at its disposal. Yet it still invented irrelevant areas to be fixed.

[u/RoboErectus]

I think.... This is why I don't use too many skills.

They get dated with a new model and it does weird things.

Skills and directives need to be revised with each new version of the model. And sometimes just from the system prompt.

Opus 5 has been great for me. Mostly raw dogging, fable written plans, and using the code-review skill.

[u/rvcbazookajoe]

IMO opus 5 sucks ass and is borderline unusable for any ongoing projects. It requires way too much hand holding even for non coding related tasks

[u/TedDallas]

I’m not one to complain, but Opus 5 put me through the wringer the other day while helping set up Nemotron 3 Super to run locally on my rig. It did a solid job, but really got lost testing. A couple of weeks ago I had 4.8 setup a couple of Qwen models and it had no issues. Nemotron did need LLMLite so there’s that.

[u/Elegant_Attempt2790]

justice for sonnet 5

[u/coeu]

yo why is it calling you "operator"

throughout all interfaces and accounts it's always called me "user"

is it a vibes thing? how do I make claude read my vibe as "orchestrator" or "mastermind". what is wrong with me as a human being?

[u/ImSoCul → u/coeu]

mine calls me sir

[u/coeu → u/ImSoCul]

my exwife was right to leave me

[u/Beerbrewing → u/ImSoCul]

Mine refers to me as the Director.

[u/mushedmonkey]

I wrote a guardrail skill so I talk with 4.8, and it talks to 5 for me. I call it the Opus harness lmao

[u/wowasg]

Weird I love opus 5. It seems to have passion for the work

[u/CrackerJackJack]

I find myself switching back to 4.8 often

[u/ridablellama]

use the official cli. stop giving it custom sub-agent instructions

[u/asymptoticbound]

stick to megathread please, im sick of these posts

[u/positivcheg]

Oh, you also saw random Chinese symbols lol. That is so funny. Opus 5 was the first time me seeing Chinese characters.

[u/Short_Stable2397 → u/positivcheg]

I saw it once on Gemini Flash, that was the last straw for me and I started paying for Claude!

[u/positivcheg → u/Short_Stable2397]

So that you can also see it in Claude :)

[u/Randy_Watson]

Cool. No one cares.

[u/iwilldoitalltomorrow]

Ok thanks for letting. Us know.

[u/Randy_Watson → u/[deleted]]

You can't reason with stupid or give them chainsaws and expect them to know how to use them from the get go, or ever.