I read the book a couple of months ago, right before Left Hand of Destiny
and in preparation for jumping onto IKS Gorkon
I enjoyed both the past as well as the present plotlines. It added depth to that alien civilisation that we got to see more of their heroic age, similar to Kira's visions of ancient Bajor.
The only downer is that Kahless II's descendance from Morath never comes up again.
It is a great read, Imho!