I've been trying to push myself to use Codex Spark more, mostly because the speed changes the workflow in ways I'm still wrapping my head around.
My main tools are still Codex 5.3 on high reasoning or Opus 4.6 (usually through @RepoPrompt), but Spark is fast enough that it makes me rethink what's worth handing off.
When regular Codex disappears for 30 minutes on high reasoning mode, you learn to run multiple tasks in parallel and context-switch between them. Spark doesn't need that pattern. The speed drops the friction enough that I'm less precious about what I delegate.
I'm developing a mental filter for it. Docs updates after a code change? Spark's fine. First pass at demo code? Sure. Scanning docs and suggesting rewrites based on a PR? Worth trying. Complex debugging? Not there yet.
The reasoning isn't strong enough for gnarly bugs, but the speed makes it useful for a different class of task. Still early days figuring out where it fits.
Are you using Codex Spark? Has it carved out a specific role in your workflow, or is it just another option you reach for occasionally?
strickvl