What's especially fun is the "Occupations." My favorite: "Occupation: Holy Roman Emperor." Of course, real genealogists frown upon having this much fun and making such rocketing connections; but some student of Latin has kindly looked up the kings' lists and simply transcribed them. Good enough for me. Our Jacobus may turn out to be not firmly connected to the John Nevil (or whomever de Neville)changed the name to Usher, but that gap is small, historically--only from late 1100s to late 1300s; and from that generation of de Nevilles backwards it is easy and fairly solid because they're all royals or marrying into royal houses. So, just to even imagine a possible connection is enormous fun and very satisfying: not because they're royals, but because they're named and dated--now right back to the kings of the Franks B.C.
Personally, for me, the fun & interest is that it sends me sideways to look up the surrounding history. I did a little of that when I first came across the entries somebody had kindly volunteered which put the line back to Charles Martel; but there's bound to be masses more, years of proper reading in history about the formation of Europe and the movements of those barbarian tribes. In fact, just knowing we were in there somewhere is enough to keep me reading the histories for decades, quite happily. I have no need for exact particulars, though they are nice. I like a good run of history with one's family line known to have been a part of it. You can stop at any point with any name so far known and graze contentedly on surrounding history; then move to another pasture and another time. In fact, they should teach history at school by turning the kids loose on their family genealogies. Endless possible projects.