A very respectful and detailed treatment of the City-State of the Invincible Overlord. The maps have been cleaned up while remaining faithful to the original. The writing is good, drawing upon the original (same locations, same shop owners) often expanding an idea into something a bit more coherent and readable. For instance, the menu at THE SILVER GOBLET remains the same, but the business is better described and the 9th level Fighter that owns the Inn now has some magic gear available (should you choose to use it).
The product also includes a remake of WRAITH OVERLORD, which details many of the regions beneath the city. I had not expected this and was very happy to discover the extra value added to an already loaded product.
This helps to explain the almost 300 pages of text and maps. The CSIO descriptive text of the town is still fairly brief, but adding a large expansion did, of course, increase the page count by a great deal.
The only downside that I can see is that the maps are all inside a PDF. You will have to have a tool to extract them if you wish to use the maps with VTT software, but once extracted and assembled, they range from large to massive.