So I did read F&B in January. I enjoyed it for the history. I enjoyed following the Targ dynasty. But the plethora of names and events along with the similarity of names and events made it a bit clunky. I'm the guy who reads history and listens to podcasts for fun... and yet my lack of familiarity with history of Westeros makes F&B sink into a haze. And since this is presented as written history rather than a written account of an oral tradition (i.e. The Silmarillion), I find myself annoyed by gaps in my knowledge, skipped events by the historians, and purposeful enigmas by Martin. What it really does is demand a rereading of ASOIAF... again.
Don't misunderstand me (or mayhaps, let me be clearer), I enjoyed F&B. I recommend it to loyal fans of ASOIAF, of fantastical history, and of dragons. But you will not (at least, I did not) comprehend it all.... and the story will not take you from Aegon the Conqueror to Daenerys Stormborn... it stops halfway because... Part Two is Coming.