Earthdawn is D&D that shows its work, so it was only a matter of time before it did a Lankhmar. Fafhrd and the Gray Mouser's adventures are deep in the game's DNA, so you've got to have a shady and corrupt adventure town. Some settings have even more than one. Earthdawn itself actually has at least three that I can count - Kratas, Bartertown, and Parlainth, though Kratas is probably closest. So how does Kratas: City of Thieves stack up?
It's a really good campaign book, but it's a rare example of Earthdawn failing to elevate the material. You could just run a game in Lankhmar. Which isn't to say that there's not some fascinating lore connections to the rest of Barsaive, but it doesn't quite catch the tone that makes an adventure town work. It's so bleak. Three times the book takes a break from describing the town to do some Kratas-based fiction, and the first time it's a rural Thief who comes to Kratas and gets absolutely rolled by all and sundry, until he winds up fleeing back home, less his wealth, equipment, and one of his hands. It's a cynical shaggy-dog story that's just a little too mean-spirited to sell the punchline. Like, the narrator was a Thief adept, i.e. someone who was so thoroughly in tune with what it meant to be a thief that he gained magical thieving powers. Seeing him get knocked down a peg is one thing - he was previously the biggest fish in a small pond and now he was going up against true pros for the first time in his life, but it's not to the book's benefit that Kratas defeated him. The last line of the story is "I wondered if I could still plow a field with only one hand." Kratas is "the city of thieves," but its role in a campaign is to be a city for thieves. It's the place where you have these crime-themed adventures and blur the line between "treasure hunting" and "grave robbing." So it would help if the book depicted a learning curve. It's the first time we see the town and the first person we meet inside it is someone who washes out. The lesson is supposed to be "Kratas is a tough town, meant for real badasses," but it comes across more like "Kratas is too unforgiving to be much fun."
Similarly, the second piece of fiction has a classic crime adventure setup - a naive criminal gets their hands on a score that's unexpectedly hotter than their usual fare and has to find a way to stay alive long enough to unload it, but then it takes a weird left turn where she randomly (within the context of the story) runs into the one honest merchant in Kratas, and then as she's walking away with the loot, she's unceremoniously slaughtered by one of the city's violent muggers. I'm not sure how it should have ended, but I do know that I wound up regretting getting to know Sorella, the dwarf Scout, which is maybe not something you want in a piece of fiction. She was kind of charming, and then she died . . . okay.
Finally, the third piece of fiction is just terrible. It's a sleazy tale of implied human trafficking and for, like 80% of it, I thought they were building to a punchline where the cynical Troubadour was going to wind up destroyed by the naive young woman he was attempting to exploit (maybe it's just me, but the line "I'm glad I could find someone like her. I might be in some trouble if I hadn't" seemed like a setup for a rug-pull). In the end, though, he successfully "persuades" her to become a prostitute and we're treated to some lovely and entertaining speculation about her current and future earnings. It's funny, because this story might have worked if it had ended like the first one - with the narrator being ruined because his cynicism was insufficient to the realities of Kratas. It might actually have been satisfying to learn the tough guy wasn't tough enough for the tough town because he underestimated female agency.
What this all adds up to is a dark, noirish setting where all the heroes are tarnished and death is waiting around every corner, and it could make for a very compelling Sin City-style game, but Earthdawn is a (well-made) D&D clone, and thus it leaves some buckles in desperate need of being swashed.
If you can bring that essential element of chaos (and frankly, I've never known a group of PCs to lack much in the chaos department), then what you'll find is a thorough and generous campaign book. It's more than 200 pages long, bigger than even the 1st edition boxed sets, and its filled with diverse neighborhoods, so many npcs they need their own special index, dozens of inns and taverns, numerous adventure hooks, and a two-page spread that reprints one of the original Legends of Earthdawn. In terms of sheer, factual information, you're going to be covered.
I think the main reason I've been so hard on Kratas: City of Thieves is because for all its elaborate worldbuilding, for all its (admittedly bleak) humanism and keen attention to politics, it misses a small, but significant part of the Earthdawn formula. It's so busy being a Lankhmar that it forgets to be a well-justified Lankhmar.
There's a line that sums it up for me - "most residents of Kratas now realize it is in their best interest not to molest the farmers." It's kind of hilarious in context, because one of Kratas' few laws is that the thieves are not allowed to steal from farmers on their way to and from the food market (robbing them at other times is fine, though), and so you basically decode this as "living in a town is easier when the local government performs even the basic functions of local government." The unavoidable follow-up inference is that even more security might make the town even easier to live in. In fact, the City of Thieves as a whole would be a lot more pleasant if there weren't so many thieves everywhere.
It's got to be something that is on the mind of not only the towns' residents, but all the major powers of Barsaive as well. Kratas' whole reason for existing is to be a place where thieves and raiders can go to sell their ill-gotten goods, and thus it is at best a nuisance and at worst a threat to every honest settlement in the region. It is a rogue state, and thus essentially unstable. It can exist only as long as the societies it preys upon are unable to project military power into their borders. Throal or Iopos or even a town like Jerris is going to be able to roll over them in a war, because the closest thing that they have to a government is a gang that collects protection money and only intermittently provides protection (to farmers, in a particular neighborhood, at particular times of day). It can only exist tenuously, in that narrow sliver of time where the world is still post-apocalyptic, when the land is sparsely settled enough that statelessness is not a fatal disadvantage.
Honestly, it's debatable whether Barsaive is still in that condition, as of the game's start date. It must be, because Kratas still exists, but it appears 3rd edition is set post- Prelude to War, so things we know Barsaive has is armies capable of marching long distances, militarized airship fleets, and professional espionage operations (three things Kratas can't afford because the revenue of its most powerful gang is purely private profit). By all reasonable accounts, Kratas is living on borrowed time. It will soon either become a true state or be destroyed/absorbed by one.
The only thing in the book that addresses this is one of the secret societies, The Magisterium Resurgent. They're trying to restore the system of government that existed before the Scourge and honestly it's a little weird that they're the only ones who see this opportunity. The city should be filled with people who believe "Kratas should have a system of government . . . my system of government." But the one and only example of such beliefs are a cult that worships a dead tyrant. "Inventing the new Kratas" really should be one of the major campaign models.
Now, we're close to the end of the post so I want you to take almost everything I've said and throw it in the garbage, because my final verdict is that Kratas: City of Thieves is a really good rpg supplement. It may not be exactly on target with its genre or especially well-observed politically, but it does have lots of stuff that will help you run a roleplaying game, and in the end, isn't that what's most important?
Ukss Contribution: Also, it has a bunch of fun setting stuff. Berry Blossom, the windling Horror Stalker. The pissed off shepherd who becomes an assassin and uses his crook as his signature weapon. games of chance that are elaborate religious allegory.
However, my favorite thing was the Darks, a bar that's accessible only by one of about a dozen secret passages. It's favored by spellcasters, and some of the secret passages might actually be mystic portals, but even if it were totally mundane, I'd like its over-the-top mysterious vibe.