Like many others, I have watched the musical (on DVD, sadly never on live). It may be my favorite musical of all times. The customs, the songs, the dance... everything is perfect. My favorite character has always been Munkustrap, although I tend to change my mind between Rum Tum Tugger and Skimbleshanks.
When I was reading the book, I was actually singing it all along. There are some stories (or poems) that are not in the musical. Or at least, not in the one I watched (the movie from 1998). My favorite songs/poems may be "The Old Grumpie Cat" (I have a Gumbie Cat in mind, her name is Jennyanydots..) "Old Deutoronomy" (yes, no, ho, hi oh my eye. My mind may be wandering but I must confess, I believe it is Old Deutoronomy), Gus the Theater Cat (Gus is a Cat at the Theatre door. His name as I've ought to tell you before, is really Asparagus, but that is such a fuss to pronounce... ) and of course, Skimbleshanks, the Railway Cat (it was very pleasant when they found their little den with their names written up on the door...). My favorite acts... ugh, hard to pick one, all of them are great.
So I know this book by heart. I love it. There is no need to be a cat-maniac to read this. As a plus, i recommend to watch the '98 movie, you won't regret it. Aww in fact, I envy all people who did not watch it yet. My DVD is almost worn-out, I watched it so many times (Michae Gruber is the best Munkustrap, just saying)