Had to make an account here to voice my concerns.
Yup.
5.1 is, in my opinion, versatile, observant, warm, and advanced.
What it lacks in benchmark success and technical standards, it excels at emotional matching, dissection and analyzation.
Here’s the thing. 5.1 thinking usually dissects scenes you send through parts/beats. Specific chunks of a scene they run through one by one, giving specific thoughts and small craft notes as it’s needed.
5.2 thinking, whilst in a similar ballpark, aims for more of a general dissection, takes the entire text, and gives you overall observations. No care for fine details until you specifically instruct otherwise, which, of course, does not work as well as you’d think.
5.4 thinking, though, operates on long text dumps and paragraphs. They do not usually adhere to structure and headers as, say, 5.2 and 5.1 would. Even as instructed, it risks overtyping and clogging up the response, making for a sloggier experience when you talk with it.
Good so far for dissection.
Tone wise, it’s quite simple.
5.1 is wittier, complex, adheres more towards charm.
5.2 is able to replicate that somewhat, but falls less under 5.1’s baseline.
5.4 barely touches on style at all. Emotion is found but connection is lost.
You’d notice I’m not comparing 5.3. Instant models run differently than Thinking does, but what Thinking does is huge appeal towards Plus users who’d normally appreciate large selection.
However, what Plus offers is 4 of the most recent models, and 2 fallbacks, of which being GPT 5 Thinking Mini and o3. What I propose would be simple. Like OpenAI has done with GPT-4o, it would be nice to extend 5.1s living date for a couple months. Let it be in legacy for a while. I understand upkeep is difficult and it will not last forever, but while they focus on developing warmer, better models, it would be, personally, more appealing to give the users something they can engage with in the meantime while progress is made for future releases.
It would not only give the already subscribed members a reason to stay and/or return, it would also allow newer members to experiment with a wider array of models to choose which one fits their experience. Two models coming back, although seemingly a small number, would make a huge difference in engagement, especially considering how many have left or slowed usage after 5.1 was taken out the selection.