I assume that you've seen the table of contents in the sneek peek. (You're the same Toa who was asking about Ancient Magic at RPG.net?)
The book has descriptions of Medieval towns, Medieval city governance, Guilds, the lives of Craftsman and Laborers, Merchant organizations, lists of what trade goods are produced in what places in Eurpoe, and more along these lines.
The book has something on the order of a zillion story hooks.
For additional optional rules presented in the book you have:
The labor points system to give craftsman, laborors, and merchants things to do with their downtime in a maner not completely unlike magi but much, much simpler.
You have a few new virtues and flaws
One of the new virtues allows the crafting of limited enchanted devices by skilled craftsmen and there is a fair quantity of descriptive mechanics for this.
There are simple mechanics describing how long it takes a cratsman to create particular items and how high of quality the created items are (basically target numbers to compare to stat + skill with modifiers for raw materials and quality of the workshop that can be ignored unless you've got a PC who wants to improve their setup)
There are rules for ship to ship combat (drawn from the Ars 5 combat rules, don't expect to find a rewrite of wooden ships and Iorn men here)
IMO most imortantly there are excelent tables and maps deliniateing how long and by what methods one can travel from one spot to another spot within Mythic Europe.(which would have been even better if they explicitly marked where the junctions are rather than relying on the reader's geographic knowlege)
There is a price list accompaned by a moderate strength warning that price lists should be used with caution if you want a particularly historical game.
There are some rules for locks
I think that I'll use the book a great deal. I've already made use of the example craftsmen characters for a few NPC's. I've also made use of the travel inforamtion/rules, the ship information will probably come up in my next session.