I really liked the cultural information included - roads, several overlays to help orient things, eclipse duration lines, etc but the thing I liked the most was the rich data about the part of the path that includes my family's original land here in Texas. It turns out that both sides of my family settled land that is very near the totality centerline of the eclipse with a duration exceeding 4 minutes.
Your addition of layers that define boundaries for parks helped me locate an archaeological site that I had never heard about. While access is not available to the public I was able to research it and read the description of excavations and conclusions about the history of the site. That really made my day since it connected some of the things my Dad mentioned about the area where he was raised with a real historical site very close to the places he described.
Too bad we don't own either of those parcels today. I am probably going to experience the eclipse with a sister who lives a few seconds outside the 4 minute line since my own home is at a 99.7% eclipse location.