I'm still absorbing all 328 pages of what is so far some awesome work. Since I'm in the middle of a Kingmaker (Pathfinder classic) conversion, rules to run kingdoms and warfare are a big deal. From experience having run the campaign 10 years ago and today, I think Colville is onto the right idea as he posits in the product.
We don't want domain (whether it be kingdom or mercenary or thieves' guild) management to become such a mini-game that it overwhelms the fun of what makes D&D awesome. It should complement what you're already doing, keep the PCs in the spotlight, and spur new adventures.
Awaiting my hardback to add to my shelf and awaiting some playtest once I fit this into our ongoing game.