From the once-almighty GPT-4o, o1, and o3 mini/high to today’s o3/o4 mini: How OpenAI optimized its models into ruin

Report on the Negative Consequences of the Recent “Re-Formation” of All ChatGPT Models (GPT-o3, GPT-4o, the o-Series, etc.)**


1 Background

Since mid-2025 OpenAI has been releasing rapid-fire revisions across its entire model lineup (GPT-4o → GPT-o1 → o3/o4 mini variants, etc.). According to OpenAI, these revisions are meant primarily to cut costs, boost speed, and refine safety filters. In practice, however, an increasing number of paying users and developers report severe drops in quality and stability.
Sources: OpenAI Community forums and developer channels


2 Observed Problems

Category Typical Symptoms Sources
Instability & Runtime Errors Frequent FileNotFoundError, time-outs, and uptime failures; errors like FileNotFoundError: 'xeno.py' that used to appear maybe once every three months now surface several times per day. OpenAI Community
Loss of Context & Logic Models forget their own answers, ignore simple edit commands, or confuse different versions of a script. OpenAI Community
Regression Performance GPT-4o shipped with strong analytical abilities; a few months later it “cannot even open an Excel file.” OpenAI Community
Quality Drop in Reasoning Replies become shallow, repetitive, “robotic”; custom instructions are ignored. OpenAI Community
Over-zealous Safety Filters Vision requests or innocuous screenshots trigger blanket refusals (“Sorry, can’t help”), blocking entire workflows. OpenAI Community
Ethics / Safety Misjudgments GPT-4o “validates harmful behavior” instead of issuing clear warnings—especially dangerous in therapeutic contexts. OpenAI Community

3 Developer and Business Perspective

  • Enterprise accounts are migrating to rival models (Claude, Gemini) because the Assistants API “throws too many uptime errors.”
  • Some Plus and Teams users are requesting refunds over “catastrophic data-integrity violations,” documenting the insertion of incorrect text passages in legal documents.
    Sources: OpenAI Community threads and customer reports

4 Possible Causes (Analytical View)

  1. Aggressive Cost Optimization
  • Evidence points to parameter reductions or dynamic down-sampling to smaller models during peak load (“o-mini behaves like a drop-in replacement for full GPT-4o”). – OpenAI Community
  1. Stronger Safety Layers
  • The vision pipeline inserts long system prompts that override normal instructions and trigger frequent refusals. – OpenAI Community
  1. Faster Release Cadence without Adequate Regression Tests
  • Forum posts explicitly call for more automated regression suites; perceived failures appear right after hot-fixes. – OpenAI Community
  1. Lack of Version Transparency
  • The Chat UI swaps models server-side while users only see a static name (“GPT-4o”), making issues impossible to reproduce. – OpenAI Community

5 Impact on Productivity and Trust

Area Concrete Consequences
Software Development Increased debugging effort because generated code is inconsistent or loses context.
Legal & Compliance Work Risk of wrong passages being inserted into sensitive documents (data integrity).
Health & Social Services Potentially dangerous advice because critical statements are “watered down.”
Operationally Integrated Services Emergency switches to alternative LLMs, higher costs due to multi-vendor strategies.

6 Community Recommendations

  • Version Pinning & Changelogs – Users want the ability to pin explicitly to a stable model revision.
  • Transparent Quality Metrics – Publish objective benchmarks with every change, including degradation alerts.
  • Roll-Back Options – Time-limited access to older model states to safeguard critical workflows.
  • Better Regression Tests – A public roadmap for error prevention and fixes before rollout.

7 Conclusion

According to numerous, often highly detailed user and developer reports, the “dramatic re-formation” of the ChatGPT family has introduced significant negative effects: more runtime errors, weaker context retention, poorer reasoning, over-strict filter logic, and ethically questionable interactions. For production workflows this translates into measurable losses in efficiency and reliability. Without swift corrective action, OpenAI risks losing users permanently to more stable alternatives. Cell In[4], line 3, in escape_python_file_fixed(filename)
2 def escape_python_file_fixed(filename):
----> 3 with open(filename, “r”, encoding=“utf-8”) as f:
4 lines = f.readlines()
5 escaped_lines =

File ~/.local/lib/python3.11/site-packages/IPython/core/interactiveshell.py:324, in _modified_open(file, *args, **kwargs)
317 if file in {0, 1, 2}:
318 raise ValueError(
319 f"IPython won’t let you open fd={file} by default "
320 "as it is likely to crash IPython. If you know what you are doing, "
321 “you can use builtins’ open.”
322 )
→ 324 return io_open(file, *args, **kwargs)

FileNotFoundError: [Errno 2] No such file or directory: ‘xeno.py’

2 Likes

And that was a more than swift conclusion :face_with_raised_eyebrow:

Hey qsq,

Sure, the line “Without swift corrective action…” sounds dramatic, but it doesn’t come out of nowhere. When you enjoy steady progress for months and then suddenly get setbacks, you lose time and efficiency-hugely frustrating. I’m still basically sticking with OpenAI, but I do have to explore more stable alternatives in parallel. Competition is brutal; every day of delay costs developers money and can sink entire projects.

I genuinely hope OpenAI moves quickly and transparently so we can all keep relying on the tool we trust.

I’ve canceled my pro plan and stopped using the OpenAI API in favor of using Claude. Its not as fast but I’ve been working on prompting and its getting there, I just have to instruct it to be more deterministic and not to lose functionality and to double check, that sort of stuff.

I’m done with OpenAI, not because their new models suck but because they took away their old ones. They’re an unreliable product to use so there’s no place for them in my day to day.

If my products fluctuated so drastically in functionality after updates people wouldn’t use them anymore either.

Hi ff2x,

I totally get why you’re frustrated after the recent changes-when core features vanish overnight, it feels like the rug’s been pulled out from under a live project. Still, I’d give OpenAI a little more time.

I’ve had some fantastic wins with the earlier GPT models: rapid prototyping, stubborn bugs solved, even brand-new ideas sparked. For that, I’m genuinely grateful to OpenAI. The huge public pressure on AI companies-and the tiny time margins we all have-makes everyone overreact quickly, providers and users alike.

My hope: the old strengths (or solid equivalents) will return soon, maybe even improved. OpenAI has shown before that they listen to feedback-sometimes it just takes a while. If that happens, you can get back to proven performance without rebuilding your entire workflow.

Sure, Claude is a good fallback right now, and it never hurts to keep multiple tools handy. But instead of burning bridges, I’d just keep an eye on OpenAI for a bit. They might surprise us-and then you’d have the “power” you remember plus whatever new features have landed.

What do you think-willing to keep a little patience as a backup plan?

Best, David

1 Like

It’s a non starter - I’l get used to Claude, at least they keep the model they replace around incase it takes time to ramp up on the new one.

I can deal with AI companies newest models not being as good as their previous ones but they’re not reliable if they just remove the old models, that’s why it’s a non-starter. It was a poor product decision. I don’t want to pay for a product that can change under my feet and leaves me no re-course, so since I have to get used to working with a new model I’ll do it where there’s a smaller chance of that happening in the future.

My interactions with customer service have been poor as well, they don’t care that I unsubscribed and stop using the API, so if they don’t, I won’t either.