Here are two soundboards.

Nearly identical materials.
Same bracing pattern.
Different brace shapes.

This shows the sloped braces.

And from the side....

And this shows the scalloped braces.

Both tops weigh exactly the same.
How do you think the braces will bend differently?  How do you think that they might sound different?

Here a front view of bracing pattern.  (Adapted from Traphagen.)