Black Walnuts: All they're cracked up to be?

When we moved into our home six years ago, there were two black walnut trees (Juglans nigra) within our little lot. One was in the backyard, a mature tree planted in a very, shall we say, DIY-looking raised bed walled by concrete rubble pieces. The other was in the front yard, a younger tree with a slender trunk that split into a Y a little ways up and …