I'll second The Shadow Campaigns by Django Wexler, first book is The Thousand Names.
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Biggest difference you'll notice from Powder Mage is 1) The magic is very much in the background and 2) Women in the society, the main protagonist is women who disguises herself as a man so she can serve. One of my favorite thing of Powder Mage was the modern stance of women in society. They fight, serve, and die the same as men and are treated no different when they gain power.
I'll second The First Law. In addition, I'd recommend Django Wexler's Shadow Campaigns for another low magic setting.
In terms of grittier fantasy, I'll second the recommendations for Joe Abercrombie's works. In addition, you may want to look at Django Wexler's Shadow Campaigns, starting with The Thousand Names. It does have some fantasy elements, but it's primarily a military and political story.
The Lies of Locke Lamora is a grittier story focusing on a crew of thieves. It's not as politically focused as Song of Ice and Fire or the Shadow Campaigns, but if you like heist stories, I'd definitely recommend it.
Check out the Thousand Names by Wexler. Really goos read, and the last book in the trilogy will be out in a couple months. http://www.amazon.ca/The-Thousand-Names-Shadow-Campaigns/dp/0451418050