In addition to reach, SRAM generally has a shorter "throw" of the levers than Shimano b/c you only push the inner lever. That can make a difference for someone with small hands. The newer and/or fancier Shimano stuff (new Ultegra or DA / old DA) won't be as hard (forceful) of a throw for the large lever, but it still requires more effort than SRAM.

That said, I'm perfectly happy with Shimano, but I am not petite, nor do I have small hands.