I get what you're saying about settings being more accessible in Urban Fantasy novels, but I don't believe it's because the authors are inherently more talented. If you have semi-humans throwing energy around in Manhattan, the reader knows there's a Statue of Liberty lurking. But if your heroes live in Westeros, a place that only exists as much as the author tells us it exists, you won't see the Titan of Braavos until the characters do. That's why some works of fantasy can feel contrived, and why setting (and how it's conveyed) is so important in a masterwork.
To my mind, it goes back to the idea that urban fantasy is easier to get into than high fantasy; the reader doesn't have to walk nearly as far to meet the author halfway. The only things that are different in Dresden's Chicago are the things he tells us about.
The setting troubles that you're having, are they about setting the story, or setting the story in the real world? I don't think you'd have much trouble plopping a starbucks where there isn't one, your readers aren't like to punish you for it. If you're blocked with setting in general, you could go back over some mechanics of writing stuff, remind yourself of the fundamentals of setting and come back to it fresh.
If that doesn't work, I suppose you could sacrifice a beanie baby to the gods of frustration. That usually works for me.
