Even watered-down Heinlein is worth the time investment. Pournelle gives it a valiant try, but I have to wonder why a character with admitted temper problems allows *everyone* he meets to withhold information so obviously.
It's actually a better read if you skip chapter 12, where the author tells you the backstory of Earth, and chapter 13, where the villain broods and explains his motivations to himself. The only effect this has on the story is to spoil the reader's surprise when the villain is revealed to the protagonist later, removing what little mystery the plot has.
Sorry, fans. I really wanted to like the book more, but it fought me at every turn.