Wangfujing is less than a kilometer from the center (Tiananmen), and it's difficult to reside much closer.

But, if you are inclined to explore spots around 3rd or 4th ring (or even further out like the Great Wall), being downtown is arguably less convenient being than a little further out (e.g StR just outside of 2nd ring and a bunch of places are on 3rd ring between Shuangjing and Sanyuan Qiao).