Are U-shaped or X-shaped table legs better?

We weld both shapes in our own workshop. U legs are two closed steel frames: a calm, rectangular line with no apron or stretchers and full legroom along the table. X legs meet in a tightly welded node, look lighter and more sculptural, and get their stiffness from the diagonals alone. Choose U for a simple, solid table and X where the base should be a feature. Compare the common base shapes.