It's always a bit sad to hit the end of a series, especially one as engrossing as Wells' Raksura books. World building is a term that gets thrown around a lot--by me as much as by anyone else--but it's only after reading Wells that I remember how few writers truly build from the ground up. Wells does. Her books sometimes have an almost anthropological feel to them as the reader (through Moon) tries to figure out what is going on.
Also, madcap adventures, flying island, small children being adorable. It's fun. Honestly, if you liked the first six books, you'll like this one and, if you didn't, why the heck are you still reading?