Just picked it up today... I used to run Birthright and this looks right up my alley.
Good: They integrate economics, construction, taxation and warfare. If you are running a game with the players being the lords of a nation this is a very useful supplement indeed.
Bad: Some pretty much useless maps, lack of information on religion and magic in the running of a nation and the control of the populace, some spells specific to running a nation would be great.
Things I would have liked to See: I would have liked more information on trade, though the rules on resources was a good start.
All in all I feel that it was a worthwhile purchase. The updated Open Mass Combat System was nice. I will most likely keep my house rule of using a skill roll to operate the siege engines rather than an attack roll After all I have both a Knowledge (Siegecraft) and a Master Artillerist prestige class in my game.
I will need to read i more thoroughly tommorrow.
The Auld Grump