The previous review is pretty much on point and I don't have any serious quibbles with it. For my part, I enjoyed my read of it but would recommend printing out at A4/Letter size as it can be hard going on the eyes otherwise.
The sandbox content was good and I'd be happy to running it with the post-apocalyptic ruleset of my choice (considering OmegaLite20, Atomic Highway and The Rad-Hack). On that note, this is a mechanics-lite supplement with less than a handful of Mutant Future specific monsters being mentioned such as Ant Horrors. I don't remember any mention of spidergoats! So easy to port to the game of your choice.
The core of the book is a gazeeteer of the post-apocalyptic Southwest covering settlements, cities and ruins. The coverage of settlements and cities is pretty robust with writeups of the locations, relevant adventure hooks and faction relations. The take on Carlsbad Caverns (Big Room) was particularly inspiring, you could run a whole campaign around spelunking in the over 119 caves in the locality, because you know there is going to be lots of weird stuff to be encountered! In contrast, I felt Las Vegas (Vega) was a bit of a let down, mundane and no adventure hooks. Really? I would throw this take on Vegas out and possibly go with something has has more of a Six-String Samurai feel.
Ruins get a less detailed writeup but guidance is given on hoards, random encounters and hazards for each one. Enough for the GM to get their teeth into.
Some coverage of major topography for the region is provided before the main faction writeups. Six factions are detailed, four of which are mentioned in the faction relations section of the location writeups. Out of those four, The Cartel doesn't feature in any of the location writeups and adventure hooks. Given the natural fit with Vega as acknowledged in the faction relations section, that seems like a missed opportunity. As the BBEGs of the setting, the coverage of the 88th was adequate but would have benefited from more details. The same goes for their hometown of Springtown.
The remaining two factions I have mixed feelings about. They both feel tacked on as they aren't mentioned anywhere else in the book. One of them feels almost entirely useless except for providing PCs with access to a very specific mode of transportation. If that doesn't figure in your game, they are entirely useless. The second is more promising as it potentially ties to the Groom Lake/Area 51 ruins and the underdeveloped alien thread in the book.
I have written up pretty extensive notes based on my reading and put together a GM binder for running a sandbox campaign in the setting, sourcing the relevant material to support that campaign. So all in all, this supplement does what it intends to do, provide a foundation for a post-apocalyptic Southwest sandbox. Beyond my critiques above, pretty much the only other thing I could ask for would be a few major NPCs to represent the factions and locations. Other than that, I'm good!