As a child, I had fond memories of this story, and the novelisation was the book I read most often. I recall once actually finishing it and turning straight back to the first page to read it again! Terrence Dicks, stalwart of Doctor Who publishing, turns in a better than average book, adding to the basic story to flesh out character backgrounds and provide information about what happens to characters after they leave the story. In listening to this audiobook, it was this aspect which impressed me most.
The other impressive aspect is Tom Baker's reading. He brings to life the characters on the page, imbuing them with something of their screen-selves. The Doctor was never more alien than in Pyramids of Mars, and this comes across thanks to the fluency of the reading. This is one audio book that I have returned to more than once.