A shame you stopped there (but I can see why). It improves slightly on page 29, and drastically on page 158. In fact, here's the version you should read, with the filler chapters omitted (all numbers are inclusive):
9-11
13-16
25
34-37
39-41
43-46
56
64-67
70-85
"The other Epilogue"-End of Book
In short, this throws out about 48 chapters worth of filler. Everything else is worth reading.
(Funny, this means that only half of the book is actually worth it).
I can land it on every pad on the map with lunar gravity, (and gotten to 100 from the start and one tank of fuel) and the first seven with Jupiter gravity. I'm curious what you folks think, considering that this uses real physics.