Well, I said I was going to read "And the Hippos Were Boiled in Their Tanks" for the title alone. And I did. My quick review, it was worth the read only after learning about the full story behind the book.
If you're a fan of or are interested in learning more about Kerouac and Burroughts it's worth the read. If you are looking for a good crime novel look elsewhere.
The first two paragraphs of the NYT review sums it up well for me.
The best thing about this collaboration between Jack Kerouac and William S. Burroughs is its gruesomely comic title: “And the Hippos Were Boiled in Their Tanks,” a phrase the two writers said they once heard on a radio broadcast about a circus fire.
The novel itself, a sort of murder mystery written in 1945 when the authors were unpublished and unknown, is a flimsy piece of work — repetitious, flat-footed and quite devoid of any of the distinctive gifts each writer would go on to develop on his own.
All the reviews are pretty similar. Good as piece of historical documentation but bad as piece of literature.
The Guardian Review