I like Pathfinder, despite my usual aversion to d20, so when I saw this, I was somewhat curious.
I like it, and I don't. On one hand, it's cool, and could be a GM tool even. On the other, it's just too cool.
I like the prospect of players owning cities. Surely some super-powerful bards, clerics, sorcerers, and the like have the brains, guts, and charm to pull it off. It's a good source of resources and responsibility, and allows fleshing out a world easily and quickly. Also, it has a wilderness exploration aspect, which is pretty cool, though nothing to write home about.
The one bad thing about city ownership is that it gets to the point where it could become either another game, or just a background trickle with an occasional effect. On one hand, I don't want an epic character defined by his ownership of a city, nor do I want an under-epic character using a city as his only means of strength.
Ultimately, like all supplements, this depends heavily on GM intervention, but requires a special amount of moderation, as it can wind up to be either an awesome addition to a campaign, or a tool for munchkins.
I like it, though, despite its flaws, and it's certainly priced decently.
[4 of 5 Stars!]