The new speed feature for Codex . What is your experience?

Apologies for the sidestep, but if you want something really fast and can handle less thinking and slightly less accuracy, try:

GPT- 5.3-Codex-Spark Research Preview with 1000 Tokens per Second Codex

An ultra-fast model for real-time coding rolling out today to ChatGPT Pro users in the Codex app, CLI, and IDE extension. From the announcement: Codex-Spark marks the first milestone in our partnership with Cerebras, which we announced in January⁠. Codex-Spark is optimized to feel near-instant when served on ultra-low latency hardware—delivering more than 1000 tokens per second while remaining highly capable for real-world coding tasks. [SWE-Bench Pro-1] At launch, Codex-Spark has a 128k…

(if you have access)

Because it is very very quick.