Hussar
Legend
I really like that map! Great to look at, and gives the designer the ability to create more three-dimensional spaces. Does the product also have a standard, top-down map, though? Because I think you'd need the utility of that as well.
Doing illustrative maps like that adds real cost to a product, but I think it adds real value as well. Both in terms of design quality for the adventure (because it adds the ability for the designer to work in three dimensions) and the production value.
IIRC this is from Kobold Quarterly and there is a top down view.
When I used this map in an adventure, I was running on maptools. I simply used the isometric view which was great. You can skew the tokens slightly to fit the isometric grid and it really adds a lot to the adventure.
Not sure how you'd do this on a tabletop to be honest. One of the Savage Tide adventures had a fantastic base for the pirates which was a bunch of ships stacked on top of each other Pirates of the Caribean style. I know more than a few people made models for the adventure that looked great.