I thought it's narrative was difficult to follow. Luca Brasi seemed undeveloped as a character mostly centered on his cruelty throwing a baby alive into a fiery furnace. Too much about a minor character.
Also too much was made about the code of OMERTI which was more the fascination of the author, Puzzo, with discovering it, than the plot line. It seemed to sidetrack the plot rather than help it move along. In short I thought it was badly written and put in print before it was thought out.
I have to keep reading it again to find a way to edit it