The saddle to top of bar drop of zero feels sluggish to me when I want to go fast.
I did have lumbar L4/L5 surgery 15 years ago but I have fully recovered from that. I find that when descending, my butt slides further back on the saddle and my pelvis sort of rotates forward, making getting into a low fast position pain free and fun.
But where the real fun with some of these realizations factor in to the “classic and vintage” world is how this knowledge of the new fast and comfortable fit opens up build opportunities for some super cool unloved vintage frames. I would love to acquire a size 55.5 Merckx MX leader or Moser with El-OS tubing for example.