I've been very leery of new books in this (sub)genre (which I'm going to loosely define as in-character found documents from the zombie apocalypseZombies: A Record of the Year of Infection: Field Notes by Dr. Robert Twombly and found that the purported "year" began in January and ended in March. I didn't intend to buy this; I was just browsing, and then I turned the page and one of the notes actually made me flinch, and I decided "okay, worth the money".
It's a very fast read, which is a bit saddening; I wanted it to last longer, but I think having twice as many notes would grow overwhelming. You'd either end up with a glut of snapshot moments, or end up following people through the notes they left (which minimizes your brain having space to play so freely with who they were and what happened).
Overall: sad, occasionally funny, horrifying, cold, and persistent. Recommend for people who like zombies, people who like prop documents, and probably fans of Post Secret.
 I do, however, love that there are enough of these books that I can say that. I own four, myself.