TL;DR: Superb fluff, world, background and non-rule-stuff 5/5. Good ruling ideas (FLOW) 4/5. Poor ruling explanations. 2/5.
First things first: This review does not review it from a 2012 standpoint, but from a 2021 standpoint. Therefore I will openly critizise thigns that were o.k. back then, but are no longer acceptable nowadays.
In this second part I will mainly focus on the rules, because the rest is - as stated above - perfect.
I have never played a diceless system before nor read any. I am not against diceless systems. The system presented is in general very interesting and I think it is definitely playable. However, the way how it is described is brutal and very difficult to read. Words are used before defining them properly which makes remembering information properly very difficult. Multiple reads are necessary to understand everything, I guess. One example for a word that is used without explaining it (at the time where it is used) "Hit". In a fire fight, when you lose a challenge, you can be "hit".
I do get why the author thought this was a great idea: It's not important for now, you will understand about 5-10 pages later. But 1. this leaves me in confusion 2. often I will only read about 10-20 pages per day (of a rulebook) and therefore have to make the cut before understanding what "hit" means. Compared to modern systems like TDE5, Shadowrun 6 and so on, summarization-boxes are missing when badly needed.
Sometimes the structure is not very inviting as well. The book will give you a ruling: "Sometimes you need a challenge" a fluff-text "most non-stalker people never will have a challenge in their life" and then goes ahead telling you that fixing a car is a challenge. Not very elegant. But this is not a problem per se.
At other times it gets really problematic. The challenge mechanism is "explained" without explaining enough so you can understand it. Then you get about 10-30 pages about how the challenge mechanism works. Real summarization would have helped this book a lot. Simple, numbered steps and then an explanation to those steps.
Because of the non-explicit structure the reader might sometimes wonder: Is there a structure at all? Luckily he is most times pleasantly surprised: Yes, there is. Making the structure more explicit would've helped a lot.
If the structure is reworked and rulings are explained with an explicit simple step system instead of just dumping the information, this book would get a 4/5 to 5/5 rating.
In its current state I cannot recommend it to non-STALKER fanboys since it is too much trouble to get into.
To avoid any misunderstandings: There are many explanations given in great detail about which ruling is used when and why rulings are the way they are. It is just the presentation, order and structur that I am critizising.