This traipse through cinema is classic Zizek, which means you can probably take your gut feelings towards the Slovene and figure out how you will feel while reading this book. Wikipedia is 100% right to say he tangentially discusses Kieslowski's films. However, the Zizek that does violence to a film to extract the theory from inside its gaping chest wound (I forgot who wonderfully and accurately described the Pervert's Guide to Cinema this way) is not fully on display here. For the most part he is often making smaller, more nuanced observations of the films he talks about. However, when he goes full Lacanian, he does lose me. I still cannot make sense of "woman does not exist" and I'm not sure I care to put more effort into trying to make sense of it. When he writes in a footnote: "...is Ripley [from Alien] a woman confronted with a phallic monster, or a man (a masculinized/desexualized being) confronting a primordial horrible (M)Other?" I'm not sure if this an elaborate groan-worthy joke or a pretentious trite attempt at analysis. Oh and of course there's plenty of sex and crude humor, including a lengthy footnote casting philosophy in terms of "fucking" such as Descartes' "I fuck, therefore I am." Classic Zizek.
That being said, I do appreciate Zizek's discussion of Kieslowski's films when he finally gets around to it. In my opinion, he does hit upon many of the great moments in his ouvre. While he gestures at a totalizing interpretation of the Dekalog series, offering a mapping of the episodes onto distinct commandments that is not entirely satisfying, the discussion of the themes present throughout the series is worth commending.
If you aren't here for the theory discussion, then I think it's entirely possible to skip through the book and digesting the bits that get down to the business at hand. There are fairly long sections devoted to philosophers and movies that are not strictly necessary, and I would consider the low points of the book. Even having conceded that, there is plenty of grist for the mill here and you'll come away with new thoughts on Kieslowski's films and likely a desire to revisit them.