While I've read many biographies from the era this is the first one I found of Franklin that I found both engaging and focused on reality. You don't need to be fanciful or add to the life of Franklin. He was a scientist, a journalist and printer, a diplomat and a politician and he excelled in all these roles. Without any doubt he was the most widely known and respected American of his time and one of the two most important figures in the American Revolution (George Washington being the other).
This book lays out Franklin's life well but there are some issues that could have been talked about at more length. Slavery leaps readily to mind. Early in his life Franklin owned slaves and was ambivalent about the institution. Later he became an opponent. The book does talk about how he came to believe those of African heritage were every bit as intelligent and capable as Europeans. But for such an important issue the book deals with it only briefly. This is possibly because Franklin's surviving letters and writing on the subject are brief. It isn't as if The First American ignores the issue nor does it deny it importance. The subject just seems to cry out for more detail (and this is often true in Founding Father's bios).
I never slowed down reading this except when there were long portions that included letters to and from his lady friends. Part of his history to be sure! Just not one I find interesting, even if it does serve rather definitively to humanize the subject!