Ok, I bought this as well - Bad Simon.
This is a sourcebook covering the Clanking City, aka Zistor, Zistorwal or Zistorela.
It has a not-so-pretty cover, although well-drawn, of the forges of the Clanking City and artwork liberally spread throughout. The map of the Clanking City is in the same style as the ones in Jrustela and is absolutely awful. It's dark, difficult to read and has very little detail. It's better than the ones in Jrustela, but only because it's a single map of the Clanking City, so at least they got that right.
So, what's in it? Well, chapter by chapter ...
Zistorwal Revealed describes the general background, the context of the Clanking City and how to use the book and is a good introduction.
The Zistorites covers the people of the Clanking City and has sections on Zistorite Society, The Heart of Zistorism, Zistorite Culture, The Castes, Faith and Politics, The Five Factions and Creating a Faction. These are generally good, each faction is covered in some detail and the leader of each faction is also described, although no stats are given for them. Quite a good chapter.
The Machine City starts with a map of the Clanking City that is very dark and hard to read. For those of us of advancing years, this is regrettable. Next time, include a map that we can actually see, please. This chapter is written as a letter from an EWF spy and suffers from that a bit. However, it does describe the different areas of the Clanking City fairly well, so perhaps we can forgive the style, although I would prefer a more objective way of describing things. It describes each area very sketchily and sometimes you have to fight through the opinions to get an idea of what is there. After ten pages or so, I was skipreading to get to the end of the chapter. Which is a shame.
Wonders of Zistorwal describes Mechamagical Implants, New Mechamagics, The Enslaved, with stats, Born of Factory and Forge which lists new magical weapons and items, New Spells with 6 new spells, The Great War Machines, which has rules for the construction of vast terminator-style robots and examples of such machines, with stats, wahay!
The Faces of War describe one EWF General and 5 Clanking City notables, again with no stats. These are interesting and have some potential as scenario hooks. Finally, there are 8 scenario hooks briefly described.
So, is it any good? Well, it's OK. Jrustela is better, though. Mechamagics are well described and there are stats for the War Machines, but notables are described with no stats, which is frustrating. The descriptions of the places within the Clanking City could have been done in half the space and without a lot of the fluff that surrounds them. The map is truly awful, sorry to the person who drew the map, but a different style and a clearer map would have been far better. But, on the whole, it's OK, not great and not poor.
I'd have liked to se more on the Seige, with the EWF forces described, but perhaps these will come as a Campaign Arc or series of supplements.
Is it worth buying? Obviously, if you want to use Clanking City as a setting then yes it is worth buying. If not, then it might be worth buying just for the flavour.
I'd give it a B, Good, with a Buy It 75%.