This book is a history (written in the voice of another character) and not a novel and it feels as such. There are events after events (more like tragedies after tragedies) and a list of names and places and dates which can quickly overwhelm someone who is not really interested in them.

Since it covers over a century of history and several kings' lifetimes, a lot of events are brushed over and feels rushed. Since we only focus on significant events, and as most such events happen to be war of murder or both, most of the book feel tedious (especially Jaehaerys I's reign which we were given over to think as a time of peace, but which has the most such 'tragedies'. Not sure why Martin chose to write it as such). Since this is a history, it draws from multiple sources and some of them are funny (Mushroom especially), but a big portion of the book has sequences quoted from multiple sources and adds to the tedium. Some of the stories which added to the mystique of the Targaryen history in the novels seem a let down here (Especially the 'Hour of the Wolf' - this seemed like an event which read best as an aside in the novels, but when explained, lost some of its sheen).

The book really picks up AFTER the Dance of the Dragons (last quarter of the books). Alyn Velaryon's progress and

Spoiler

Viserys' arrival

were well written. The latter especially reminds you why people like Martin's writing. But this alone is not enough to leave a favorable impression in my mind. Although, I have to say that any fans of ASOIAF will find this a fun read. Just not that fun - Targaryens are not the most interesting of the families (discounting Aegon I and Aegon IV for totally different reasons) and I feel we didn't really need two books' worth of material on them. I, for one, would love to read more about the First Men, the Children of the Forest and the Andals. But, hey, Martin doesn't owe us anything. Happy to read what comes by.