I think I enjoyed The Sleeping Prince more than the first book; Errin interests me more than Twylla because instead of being used, being a symbol, being lied to, she is a woman with skills. She’s not in the same privileged position as Twylla (who for the first book is practically a princess), and she really has to work for everything. I’m not sure I’d call her a more likeable character, but maybe more relateable.
The pacing of this book is also, I think, a bit faster; I found myself racing through it after the first 50-100 pages. Suddenly Errin has to go, go, go, whereas Twylla doesn’t manage to overcome her inertia and leave the castle until the end of the book.
That said, I’m still not absolutely in love with the book. It’s enjoyable enough, but I thought the plot twists were predictable — and the ones in this book didn’t get me by surprise like the one at the end of The Sin Eater’s Daughter. I do like a well developed twist — where you can look back and things fall into place — but predictability sucks.
If you’re interested in the world and characters from the first book, I’m sure it will be for you; the writing is the same quality or better, throughout, and though the character POV switches for this book, you will see characters you know from the previous book. I’m curious enough to read the third, when it’s out, but not curious enough to rush for it.