There's more than that though. You're right that Dresden being an urban fantasy helps us imagine the setting, but even in the fantastical side of things (the Nevernever, the White Council's headquarters, etc) he gives fairly vivid descriptions. Like the scene where he rescues Molly from the Fetches - I can form a vivid image of what it looks like as he steps through the portal into Winter, approaches Arctis Tor, climbs over the bones to get in, ascends the tower, walks through the garden of frozen statues, etc etc. The same with Demonreach, Chichen Itza, the Stone Table, Hade's vault, etc.