I started with The Broken Crown and then went back to the Hunter books somewhere in the middle of waiting for The Sun Sword to conclude. You might give The Hidden City a try, since it is probably most similar to the Cast books but also since, chronologically, it starts at the beginning of the West books.

But they are different. I could totally see fans of one not liking the other. It's actually interesting to me that she can write in such different styles.