From what I think I know.

Front sight on SD is steel and dovetailed to the slide.

SW sight goes in a small hole and might be glued in.

SW has a heavier poly frame.

SD's sear assembly and rear frame rails can be removed as one.

SW's rear frame rails are part of the actual frame.

SD has a lighter trigger pull.

SW in my opinion is easier to take off slide.It has finger grooves where the SD really has no finger indents or grooves.

Trigger springs are different.

3