Yep, I'm with Silk. The first book was fantastic, absolutely amazing and so poetic. So very well written... The others are good, I still enjoyed them. I think that the last two just got a bit caught up in the action and resolving the story. The first was so enigmatic, things weren't spelled out, she took time on setting and characters etc.
Its probably just the age old pitfall of having tension and things hinted at, being desperate to see what happens, and then feeling slightly dissappointed when the tension is gone and everything has been spelled out...