Publisher, editor and author John Morrow's chronological compendium of Stan Lee and Jack Kirby's publicly spoken words concerning their decade-long collaborations is a handy document. It's liberally illustrated with examples of the art processes discussed. It's also a good reference guide for what was said when, even when the later pronouncements become (very) repetitive as both comics creator's memories calcified. Especially insightful (and surprising to me in their depth) was the prodigious number of examples of Lee either passively/aggressively - or just aggressively - denigrating Kirby, Steve Ditko and Wally Wood in the letters pages of Marvel comics. One might believe Lee was, at heart, insecure in his writing skills.
I believe the book does come with some prejudices and presumptions. For example, Ditko is described by Morrow as a "talented artist", disregarding the fact that Ditko was a writer for most of the last fifty years (at least), personally authoring his most important published work during that time. When pages from the Disney Legends program book are reproduced, no mention is made of Kirby being a writer (before, during or after his work at Marvel) - an outrageous designation that gets no pushback from Morrow. Little to no mention is made in Stuf' Said of the plethora of comics Kirby wrote before the Marvel age. Likewise, the same Disney book states that Lee "dreamed up an endless number of new characters and worlds", a boast that is demonstrably untrue. The best evidence to decide the verdict Morrow could have presented (but didn't) is Dr. Michael J. Vassallo's definitive essay detailing everything Lee wrote before he teamed up with Kirby (and Ditko): "Stan Lee (1922-2018) - The Timely Years". It's a damning document that makes clear Lee did not create the cosmic concepts Kirby had already been creating since the early '40s (if not earlier). https://timely-atlas-comics.blogspot.com/2018/12/stan-lee-1922-2018-timely-years.html
Lastly, the book's cover, with psychedelic Captain Victory art blown up out of context and covered with large digital fonts, is ugly. While conveying some of the anger expressed by Kirby, the cover could have looked more welcoming and it's noteworthy that nowhere is the book's designer listed.