More options for anchors around the label could enhance the elegance of a map, but I would be pleased if the anchor was simply to the center of the label. With some adjustable offset, so that the leader did not actually run over the text or background, the leader would always look good -- like it was pointing to the label, not always stuck on one side. This same anchor point should give a nice, uniform, radial look to all leadered labels despite their orientation to the object -- above or below or to one side. There should be no need to fuss with any individual label's leader anchor -- automation!
Acknowledgement: This was inspired by an idea already submitted: "Leader lines should have anchor points at horizontal centre of top and bottom of text bounding box" by Wil Waters, I just wanted to stress inclusion of the center anchor, if any changes in leader anchoring are considered. Thanks.