WHAT WORKS: A good, one book overview of the setting, covering all of the major bits of the Hell on Earth. A lot of the camp has been toned down, focusing on the world being a harsh and deadly place, and that's included here because I see so many people saying that can't take the Deadlands games seriously because of the "camp" (which I've never understood, but there you go). Even if you never use the setting (or use it straight), there's a good chunk of material to mine, from Edges to Powers to Monsters.
WHAT DOESN'T WORK: Hell on Earth no longer uses Fate Chips, which makes me sad as I have always associated "chips" with "Deadlands". It also makes the Fate Eater's name a little less "on the nose". Given the sheer amount of Hell on Earth material out there, and the treatment of the Deadlands Reloaded line, you can't help but feel like you should hold off diving in and playing before the rest of the (unannounced, as far as I know) books come out. The implication that The Reckoners are just in hiding takes some punch away from the Classic adventure in which your PC group can hunt them down and kill them on Banshee, though this is also mitigated somewhat by the realization that there might not have been a ton of folks that even read that, much less played it.
CONCLUSION: I love Deadlands, but I've always held the Weird West above the Wasted West (and Noir interests me more than Post-Apocalypse), but I've sure always heard good stuff from people who have PLAYED and not just READ Hell on Earth. If this is a standalone product, and I doubt it is, it's a "really good" product. If it's the first of a new line (like I figure it is), then it's a great starting point. For my money, it's really hard to go wrong with Savage Worlds...or Deadlands. I'd sure like to play a Law Dog...or a Templar...someday.
[4 of 5 Stars!]