I just purchased this book yesterday at my FLGS and I'm very impressed by the quality of the map designs. There are a total of 5 sites: 2 large castles, 1 medium-sized castle, a tall, thick citadel and smaller keep.
The two large castles are vast sites. The first has a total of 7 levels (2 basement levels, 4 floors and the parapets). Each level of this keep is spread across 2 pages.
The second large castle has 4 levels (3 floors plus parapets) but each floor takes up 4 pages!
For those of You who will want to scan the maps, the taller castle has a generous gutter between the pages. The gutter is narrower on the 4-page levels of the shorter castle but it's still sufficient. The maps for the other 3 sites will be easier to scan as You won't need to stitch the images together.
I found that a 300 dpi scan followed by the Despeckle and then Reduce Noise filters in Photoshop produced a passable battle-map at 72dpi. (72dpi makes the grid print as 1" squares.)
In addition to the excellent maps (i.e. the "crunch"), the author also presented a good deal of "fluff" to go along with each site. Each castle is described in first-person narrative by a resident or visitor who even describes some of the people who live there or the history of the place as they know it. The inclusion of such a treatment of each site (complete with statted NPCs) was a pleasant surprise.
Something else I appreciate even more was that the maps and NPC/histories were not inextricably linked. In otherwords, unlike with trying to retool a WotC-published module, the light treatment of the sites means that the DM/GM won't need to spend ages crossing out the proper names of locations, deities and NPCs that might not exist in their world. In fact, this is partly what drew me in. There was enough flavor there to inspire me to contemplate possible settings and adaptations for my own campaign world without so much of someone else's heavily entrenched story that I felt stifled.