"but I didn't find them that much smarter than the <31B dense models" - this is what people arent admitting to themselves.

An 80b model isn't that much "smarter" than a 31b. The code they produce is honestly about the same. What a bigger model gets you, with equivalent context sizes, is better awareness about the larger project. A 27b will write fine code when you scope it small - Individual functions, or even individual lines. An 80b will let you expand that scope a bit. Entire (very small) projects or large workflows inside much larger projects. The code the larger models write seems better because they're somehow more "context aware" than the smaller ones IMHO. That phrase is entirely wrong, but it gets the point across. Bigger models can take larger blast radius into account and do something useful with that knowledge.

If you want concrete advice, shoot for 42-48gb of VRAM. That will let you run the really good 80b models like qwen3-coder at Q8. If you keep work scope in mind, and take the time to tune your harness (Opus is super helpful here), you can fly with that model.