I have it - excellent book! Another good book is "Charles Ives: "My Father`s Song": A Psychoanalytic Biography" by Stuart Feder.
I've always been a bit of a Charles Ives enthusiast. I've visited his home and family cemetery in Danbury CT. As for performances, I've preferred Michael Tilson Thomas, although I thoroughly enjoyed the 2nd symphony conducted by Leonard Bernstein.
One of my desert island recordings.
Because Ives viewed openly melodic, hummable music as not quite masculine, he always referred to Rachmaninoff as Rach-not-man-enough.