[llamasushi]

"Warmer and more conversational" - they're basically admitting GPT-5 was too robotic. The real tell here is splitting into Instant vs Thinking models explicitly. They've given up on the unified model dream and are now routing queries like everyone else (Anthropic's been doing this, Google's Gemini too).

Calling it "GPT-5.1 Thinking" instead of o3-mini or whatever is interesting branding. They're trying to make reasoning models feel less like a separate product line and more like a mode. Smart move if they can actually make the router intelligent enough to know when to use it without explicit prompting.

Still waiting for them to fix the real issue: the model's pathological need to apologize for everything and hedge every statement lol.

[umanwizard]

The pre-GPT-5 absurdly confusing proliferation of non-totally-ordered model numbers was clearly a mistake. Which is better for what: 4.1, 4o, o1, or o3-mini? Impossible to guess unless you already know. I’m not surprised they’re being more consistent in their branding now.

[deaux]

> Calling it "GPT-5.1 Thinking" instead of o3-mini or whatever is interesting branding. They're trying to make reasoning models feel less like a separate product line and more like a mode. Smart move if they can actually make the router intelligent enough to know when to use it without explicit prompting.

Other providers have been using the same branding for a while. Google had Flash Thinking and Flash, but they've gone the opposite way and merged it into one with 2.5. Kimi K2 Thinking was released this week, coexisting with the regular Kimi K2. Qwen 3 uses it, and a lot of open source UIs have been branding Claude models with thinking enabled as e.g. "Sonnet 3.7 Thinking" for ages.

[xeckr]

>GPT-5 was too robotic

It's almost as if... ;)