Reviewing GPT-5.6 is a bit like reviewing a reliable mid-size sedan. There is not much drama here, and that is sort of the point. It does almost everything competently, nothing spectacularly, and it will not embarrass you. For a huge number of people, that is exactly the right model.
Where it shines
Breadth and support. GPT-5.6 handles writing, analysis, everyday coding, and structured tasks at a solid level, and it has the widest ecosystem of tools, integrations, and documentation around it. If you want one model that does a bit of everything and is impossible to get stuck with, this is it.
Where it lags
At the edges. For the hardest coding I still reach for Claude, and for long documents and multimodal work Gemini pulls ahead. GPT-5.6 rarely wins those head-to-heads outright. It just never loses them by much either, which is a different kind of strength.
The best default is not the model that wins every test. It is the one you never regret picking blind.
The chatty problem
Out of the box, GPT loves to talk. It pads, it hedges, it restates your question before answering it. This is fixable with a firm system prompt, but you have to bother. Left alone, it is wordier than it needs to be, and that costs you tokens and patience.
The verdict
- Best for: people who want one dependable model for mixed work without thinking about it.
- Skip if: your work lives at the extremes, hardest code, longest documents, tightest budget, where a specialist wins.
- Fix first: the default verbosity. Tell it to be brief and it will be.
GPT-5.6 is the model I recommend to people who do not want to read model reviews. That is not a backhanded compliment. Being the safe, boring, always-fine choice is genuinely valuable, and OpenAI has earned it. Just do not expect to be surprised.