This reminds me of users getting blocked for asking an LLM how to kill a BSD daemon. I do hope that there'll be more and more model providers out there with state-of-the-art capabilities. Let capitalism work and let the user make a choice, I'd hate my hammer telling me that it's unethical to hit this nail. In many cases, getting a "this chat was ended" isn't any different.

Here are my reasons why this "upgrade" is, in experience, a huge downgrade for Plus users:

* The quality of responses from GPT-5 compared to O3 is lacking. It does very few rounds of thinking and doesn't use web search as O3 used to. I've tried selecting "thinking", instructing explicitly, nothing helps. For now, I have to use Gemini to get similar quality of outputs.

* Somehow, custom GPTs [1] are now broken as well. My custom grammar-checking GPT is ignoring all instructions, regardless of the selected model.

* Deep research (I'm well within the limit still) is broken. Selecting it as an option doesn't help, the model just keeps responding as usual, even if it's explicitly instructed to use deep research.

[1]: https://openai.com/index/introducing-gpts/

Here are my reasons why this "upgrade" is, in experience, a huge downgrade for Plus users:

* The quality of responses from GPT-5 compared to O3 is lacking. It does very few rounds of thinking and doesn't use web search as O3 used to. I've tried selecting "thinking", instructing explicitly, nothing helps. For now, I have to use Gemini to get similar quality of outputs.

* Somehow, custom GPTs [1] are now broken as well. My custom grammar-checking GPT is ignoring all instructions, regardless of the selected model.

* Deep research (I'm well within the limit still) is broken. Selecting it as an option doesn't help, the model just keeps responding as usual, even if it's explicitly instructed to use deep research.

[1]: https://openai.com/index/introducing-gpts/