I can not speak for Ford and their reasons for using 3D printing but I can share my experience using it in the work I do. 3D printing allows for shapes and features that can not be machined using conventional subtractive machining processes. It also allows you to get complicated parts in your hand very rapidly for testing. You can print using so many different materials now days including aluminum, stainless steel, titanium, copper... that the possibilities are limitless. Currently you can go thru post heat treatment processes to get very good material properties but they are not as good as you get from conventional raw material processes. But this technology is progressing at an amazing rate and is very exciting to see it develop.