Originally Posted by wphamilton

I think that the pads in bike shorts are mainly to absorb moisture and also prevent chafing by not moving around relative to your skin. Pads on the saddle wouldn't work very well in that respect.

Personally I don't need much padding either way, or even none at all for 3-4 hours saddle time. Everyone differs to some extent, which may be another reason the pads are split up between saddle and shorts.