James writing to me is like a huge slice of cake, there's so much decoration as well as great ingredients that it's impossible to take it all in on the first reading. As such I just love the chance to reread the whole series just prior to starting the next title in order to refresh my memory as well as having the chance to enjoy the magical world unveiling itself.
What James also does well is give the reader a world full of imagination backed with some great prose alongside some seriously delightful dialogue. Back that up with a master's touch and understanding of pace as well as characters that you just can't let go after the final page is turned and you've got a real gem of a series to enjoy. Great stuff.