This is the extended version audiobook - the original abridged audiobook with the "lost files" added in. I am not 100% sure that it includes every last word from the original book without a hard copy to reference, but it includes the chapters that I thought were important to fleshing out the in-story universe. My favorite things are the creepy music byte they play between chapters and the persons chosen to voice the added-in chapters. Love, love, love how they went for (okay, a little bit Americanized) accent authenticity.
I would recommend this version over the abridged audiobook.
As a note, my "copy" used the movie poster cover.