Yes, it’s slower than 4.1 and 4o by default and that’s expected:
It is a reasoning model, and its reasoning_effort (or effort for responses) is defaulted to medium. So it is spending time “thinking” (and costing you more tokens/money).
Try setting reasoning_effort (or effort for responses) to “minimal” and speed should improve significantly. Obviously that may affect the response quality, but give it a go.
In my experience, even the full model then becomes quite “snappy”.
https://platform.openai.com/docs/api-reference/chat/create#chat_create-reasoning_effort
https://platform.openai.com/docs/api-reference/responses/create#responses_create-reasoning