Books like King's Sacrifice

The first book of this series was incredibly slow, but it picked up enough towards the end to motivate me to read the second book. The second book was amazing, and I breezed through it in a matter of days only to eagerly pick up this. My thoughts on this book: Margaret Weiss has failed me. I've loved everything I've read by her until Star of the Guardians. King's Sacrifice was complete sludge and was only interesting for maybe seventy pages. The only reason I didn't give up on it was that I enjoyed the second book and thought that maybe this third book would be like the first and get extremely good towards the end. It didn't. And the ending was the crummiest ending I've ever read. It wasn't a happy ending. It wasn't a tragedy. It was just a flat situation where none of the characters seemed to be satisfied with the results. Highly disappointing. Apparently, there's a fourth book, but I kind of don't want to waste my time with it, but I kind of do because I want some sense of closure that this book didn't offer. I'll decide that later.