That was how Stan Lee recalled the genesis of the Fantastic Four, and how he related it over and over again through the following decades...

Jack Kirby...would later tell it differently. "Marvel was on its ass, literally, and when I came around, they were practically hauling out the furniture...and Stan Lee was sitting there crying. I told them to hold everything, and I pledged that I would give them the kind of books that would up their sales and keep them in business."

--From the Prologue

Which I read as, Stan is a simp. And it kind of makes Jack look like an asshole. Pair this with the glowing praise of some of the 70's Marvel output that I don't care for that I've read in excerpts of the book, and I'm not anticipating slogging through the muck. 

We've seen the FF #1 script that turned up years ago, so I lean towards Stan's version, especially considering how Kirby dismissed everyone else's contributions.

To me, Stan comes across in the book as the creative face of the company who really wanted to make it big outside comics - first as a writer and then in Hollywood.  He went from a very big fish in a very small pond to a very small fish in a very big pond when he went to California looking to land a movie and television deals.

Kirby comes across as being crucial to the success of the company, but increasingly embittered when he saw Stan's financial success and what he saw as a lack of proper credit.

But we're talking about a group of human beings and like in many other working relationships there were disagreements, conflicts and jealousy along the way.