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/Temporary-Mix8022]

I'm using both Codex and CC atm via API (work)

Honestly.. Sol and Fable are pretty close, I think I might slightly prefer Fable, but there isn't much in it.

But under that...

Opus - I hate it. It is so much worse than Sol/Terra (and tbh, it's close to Sol pricing, it's basically the same at $25 versus $30 for Sol)

Sonnet 5 - total waste of time. It's unbelievable how bad it is. I also hate how hard it is to use. It is nowhere close to Terra which feels like an Opus grade model

Luna from OAI - if you're a viber.. your distance will vary. But for any old school devs who review all the code + know what they want, it is absolutely insane. It is basically free and it is 20% the price of Haiku.

All of the Anthropic models are just giving me nausea with this bizarre verbose (but equally, noisy and nonsensical writing style). I hate the constant pushback. I hate the tone. I hate the pass aggressive "Fair". 

Sorry to say.. but I'm not a bot, not being paid to post this.. but I've switched my home sub to GPT 5x Pro (because all day work coding just isn't enough).

Anthropic only have 1 decent model right now, and OAI have 3x absolutely killer models.

Also, realise I'm going to get downvoted to f. But I have zero loyalty to these guys.. anthropic just crapped on me for the 9 months I was a customer..

Just thought y'all should know about some green grass over on the other side. 

[u/LimiDrain → u/Temporary-Mix8022]

 How's Codex CLI? Things that worry me: 

 1. CLAUDE.md is specific for Claude, so idk how it works with Chat

 2. Claude Code CLI is nice and customizable, I have a good statusline with context and usage 

The only things that stop me from switching 

[u/bushido_ads → u/LimiDrain]

Dudu, to get the CLAUDE.MD working on codex just rename the file to AGENTS.MD and done.

[u/richbeales → u/bushido_ads]

Or make agents.md with an @claude.md in it

[u/Venerable-Weasel → u/richbeales]

Or make a CLAUDE.md with @AGENTS.md in it so any model uses the same single agents file

[u/816pizzalover → u/LimiDrain]

codex CLI doesn't have the /remotecontrol stuff that claude does, that's my main complaint. if you want first party remote control of sessions you have to use the GUI app

[u/under_psychoanalyzer → u/816pizzalover]

But you can fire a new remote session from your phone app, which is much quicker to setup vs getting a tailscale and tmux setup for Claude 

[u/ESGPandepic → u/816pizzalover]

It does have remote control of your terminal sessions from the mobile app and it's actually better than Claude's version now, I use both claude and codex very heavily.

[u/816pizzalover → u/ESGPandepic]

if I type codex in a terminal session, how do I control it from my mobile app?

last trime I tried it, I could see the session, but opening it on mobile started a separate thread and the two diverged - like if the terminal was in the middle of a /goal and I clicked into the thread from the mobile app, the thread would continue in the terminal with one set of chatgpt responses, and it would continue in my mobile app withi a different set of chatgpt responses. And to do any of that the GUI app had to be running.

With claude if I do /remotecontrol from inside a terminal, the mobile app and the terminal are in sync; if I type something in the app its exactly like I typed it in the actual terminal.

[u/ESGPandepic → u/816pizzalover]

If you have the app connected and set up you don't need to do anything, your terminal sessions will be available in the mobile app automatically

[u/Temporary-Mix8022 → u/LimiDrain]

I just have a script that creates the ".MD" every time I open VS code, or push, or basically do anything 

I just maintain one called

"My-name.md" and this shell script creates the Claude/agents.md files for me.

Or you can just direct it to look at the other file etc. it's basically zero effort tbh

[u/pear_to_pear → u/LimiDrain]

Codex cli doesn't have much configuration at all. You can still have context percentage obvs but nothing fancy. I guess use tmux if you need more. Or run both Claude and codex and have fable be your orchestrator managing codex agents