I'm dissatisfied with this book, but having a difficult time identifying why. I think it comes down to a few things:
1. I like a happy ending. If it's not going to be a happy ending, I want there to be a good reason why, not just have it happen for shock value (which is what this seemed like to me). I get that things don't always turn out well, but this was just a festival of grief and depression and the fate of Moreta as it was written seemed unnecessary.
2. I had a hard time putting this one in the context of the world of Pern. This story is set hundreds of years earlier than the first three books, but it was really difficult for me to get that sense of place. A follow-up tie-in to the more "present" earlier books could have helped with this. I also didn't get a sense of how these people tie-in with those who are brought forward in the first book.
3. Some of the characters seemed to be there to be unpleasant for no particular reason, and I had a hard time keeping the unnecessary peripheral characters straight. If you're going to spend that much time talking about a character, let me learn more about him or her other than "they're just really annoying".

I did enjoy the story, and contrary to other reviewers I was fine having the cure found in the middle of the story; there was plenty more to go through and learn after a cure was identified.