There are no swirls or flourishes in Mike Schley's maps, they are direct translations of the terrain, with light-colour-saturation (almost watercolour appearance) which aren't all that hard on ink or toner. I think you are confusing his with Blando's opposite-of-bland style, which is full of stylistic add-ons which just increase ink/toner use and decrease readability.
No, I am not confusing him with Blando. I know of each's works. I particularly have in mind Schley's large map of the Sword Coast and the northwestern part of Faerun. Look at the ocean. See all those swirls throughout the water? Swirls may not be the most accurate word. They are lines here and there, and encircling the islands. (And yes I know, they are supposed to represent the waves.) But now look at the land, where there are moors or plains, they are all filled with that same style of lines and circles everywhere cluttering things up. There are no waves on land, so this is just a line style he uses everywhere. It's in the Great Glacier. It's in Anauroch. It's everywhere.
http://dnd.wizards.com/articles/features/map-faerün
I personally don't like it. That's my personal opinion, and I don't expect many people to agree with me. I prefer maps with a plainer color scheme, that can serve a more utilitarian role, since I use maps as tools. With a plainer color scheme, names and locations of cities stand out. With all those lines everywhere, the brain has to take a half-second longer to locate a city name. That half-second may not seem like much, but when you are using a map a lot to locate place-names, it adds up.
I do like lines to represent certain geographic areas like swamps or fens. But when he puts lines everywhere, it becomes difficult to understand where a swamp or fen is located, vs. a moor or a grassy plain. That's another problem with his style, in my mind.
I do think his art style is beautiful, but if he gave me that same map without all those lines covering every part of the map, it would look much less cluttered and serve a better purpose. All those lines sort of give me a headache. Again, he's a great artist, it's just too much flourish for no benefit.