At the beginning of the book it is rock solid, well edited and setup for fantastic execution. Though, by the time the middle rolls in and things heat up the reader begins to salivate for a good finish, that never comes. It sort of just peters out leaving you with a bit of a "really? that's it?" feeling at the end. All in all a great read for a free online book, and depending on how you feel about it you can pony up as little or as much as you like.
As for her other books, the weather warden series, I think that this book (Exile) was a warm-up to those, as (if the first is any indication) they are well written and leave you wanting more. See my Ill Wind post below.