I am a couple days late to this discussion but I used to work at a cookware store that stocked a wide selection of high end brands.

Anything that is fully clad and at least 3 ply is good. Anything more than that is major diminishing returns. For all clad I recommend the basic D3. The copper core is beautiful but I have cooked on it and don't find it makes a huge difference. Maybe in a highly controlled test you could see that it heats a bit more evenly but under real world conditions it's not something you would notice. I wouldn't recommend upgrading to D4 unless you have an induction stove, that line has more induction material in it, although tbh I never even tested that claim myself so it's entirely possible that's just marketing wank from all clad as well.

For what it's worth, I think all clad are totally decent but overhyped. Tramontina or Kirkland tri-ply pans are less than half the price and will cook and last just as well. Or if you're willing to shell out, I think I prefer Demeyere. Demeyere pans are rivetless which makes cleaning very easy and the handles are a whole lot more comfy than all clad