Bart Slodyczka dropped a brutal head-to-head comparison between DeepSeek V4.1 Flash and GPT-6 Astra. Instead of basic prompts, he tested them on four real-world builds:
an Age of Empires-style game, an animated 3D website, a booking app, and a Blender product animation. The video compares raw results, build times, bugs, and API costs slide-by-slide. Turns out, the right pick completely depends on your specific use case.
Check it out if you want to optimize your project budget.
For SEO work specifically, I'd ignore the game and 3D animation benchmarks here and test the two models on the stuff you'd actually use them for: drafting outlines, rewriting intros, generating meta descriptions, clustering keywords. A model that wins at coding challenges isn't automatically the one that sticks to a brief or writes readable product copy.
The budget angle is the interesting part though. If you're producing content at volume, a cheap model that needs heavy editing can end up costing more than a pricier one that drafts clean copy in one pass. Worth doing the math on your own workflow: take the same brief, run it through both, then track how many minutes of cleanup each draft needs before it's publishable.
One practical tip regardless of which model wins for you: keep the final editorial pass human. Use the model for first drafts and grunt work, but anything that goes on a money page or touches your brand voice should get a proper read-through. That's what keeps AI-assisted content from turning into the thin stuff that gets ignored.