I was recommended this by a friend and definitely enjoyed it. At first it felt a bit unoriginal - orphaned child bound for greatness blah blah. But it soon improved and the characters gained more depth and some more interesting characters were introduced. I found some aspects of the end a bit vague. Perhaps deliberately? On the other hand this can be good as it makes you think about it a lot.
I really liked these books although at times I found the number of weird characters hard to follow. I was also a little disappointed at the ending which left both children in different worlds with their adult life still ahead of them.