GPT-5.6 Sol's most unfortunate point this time:

It's not that it's weak, but that it can't be used yet.
Strictly speaking, this is more like a futures ticket.
OpenAI has already shown its cards, but because the US government hasn't approved it yet, the actual launch will have to wait a few more weeks.
But just looking at this card, Claude is under considerable pressure.
Sol's pricing is the same as GPT-5.5: $5 for input, $30 for output.
But it's no longer going up against GPT-5.5, but rather Claude's top-tier Mythos / Fable.
On Claude's side, it's $10 for input, $50 for output.
Sol is significantly cheaper, and OpenAI also emphasizes: on some high-difficulty tasks, Sol can reach the level of Mythos Preview using about 1/3 of the output tokens.
This point is far more important than "higher benchmark scores."
Because in real programming, the most feared thing isn't that the model is expensive,
but that it takes detours, talks too much, and takes forever to get to the point.
If Sol can truly achieve fewer tokens, faster output, and stronger coding ability, then its threat to Claude Code will be very direct.
Especially with Cerebras later on, up to 750 tokens/s.
If this speed is given to Codex, the experience could be very dramatic.
My judgment:
GPT-5.5 has already pulled Codex into the first tier.
If GPT-5.6 Sol delivers, OpenAI won't just be chasing Claude anymore, but will start pushing back against Claude.
But don't hype it up too much for now.
It hasn't truly been released yet.
For now, it's just a futures ticket that OpenAI released early.
What really matters is when it goes live in a few weeks, once Codex is integrated, whether it can actually beat Claude Code's advantages in large projects.