This is a novel masquerading as a collection of short stories. Because of this approach, the novel consists of a series of vignettes or fragments. And that is, in part, the modern aspect of it. The prose is fairly conventional, though there are a few intersting stream-of-observation passages that are very effective.
The central, and by far the longest story -- "More Benadryl" -- is outstanding. It describes the experiences of the protagonist whoring in Thailand and in Cambodia just after the Khmer Rouge. There is barely a false note in it. The other stories are not as good and have a certain artificiality about them that is missing from "Benadryl". As such, Vollmann's strengths and limitation (sic) seem both to be on display. What is good is very, very good. What is less good is still pretty good.