I've not had chance to read this book from cover to cover yet - and I'm not sure it's the sort of book that I would, not being a professional historian. But I am a Bruce. I was always being wound up at work for writing long emails - "But they tell you what you need to know", was always my response. And that's exactly what this book did for me, when I dipped into it to trace the actual origin of the family. For instance, I'd never been able to reconcile how some said that the Bruce / Brus family appeared later with Henry I, while the family name also appeared in the earlier Doomsday Book. And the book has the answer - the Doomsday entry is a (rare) update of the original, a subtlety lost in the Doomsday name lists.
The book even finds the Bruce Cenotaph again for me - my great uncle Bob had once told me about a tomb with the Bruces down each side, but that was so long ago I'd forgotten what it was. It turns out to be the Bruce Cenotaph, once in Guisborough Priory and now in Guisborough Church, with the Scots descendants of the original Robert Brus (and founder of the line) down one side, and the English descendants down the other.