I came to this more or less neutrally, with neither low nor high expectations. Thus, I wouldn't say I was disappointed. Here's the thing: King is attempting something admirable here, but it fell desperately short of a great novel. She attempts a high degree of historical accuracy, but it lacks the marvelous insight and perspective of Hillary Mantel or Maurice Druon. She attempts magic of the Old World, and lacks the poignant lyricism of Juliet Marillier or Patricia McKillip. The result is somewhere in the middle.
Another large problem is that this book needed a very good editor, and much earlier in the process. There is far too much explanation and repetition of details which should have been hinted at or appended, particularly the politics of eleventh century Scotland. The book should also have included much more material tying the reader to its characters. We are often told Gruadh is fiery and independent, and there are a few example episodes to that effect, but had it been carried out better, it would have held the reader in fondness and affection, rather than deep-mired in apathy, as I and many below readers were.
Furthermore, in novels of such particular place, as in this case Scotland, the landscape itself should come to bear as a character in itself. Frankly, allusions to Gaelic culture and language, also heavy-handed, aside, this could have occurred anywhere in the eleventh century. It is clear the King did a good deal of excellent research, but she fell in love with the facts, not the place, which those of us who already love Scotland deeply would see. Native Scots would no doubt feel this even more keenly than myself. This writer could do well by paying attention to writers who imbue the poeticism of place, culture, and love of the homeland so well into their work, and I'll be at hand with a list if she ever does.
All this said, I still recommend the book to fans of the genre. She doesn't insult you with fake magic, and she has tried very hard to put forth a theory of legendary figures who still loom large in our collective conscious today. The book was readable, and I moved through it very quickly out of desire to see what comes next. This isn't a particularly emotional novel, but it is a fun one.