Totally disagree. I am very proficient in both packages,and really enjoy using both. However, if I need to build something fast, or sketch out ideas, I go to Rhino every time. It is so much faster to build in than SW, and lets my ideas flow more.
To me Rhino is more like working in a 3D version of Illustrator. The layers, work the same (very handy for bringing parts into Keyshot), and you can draw in a similar way.
To fully define a sketch in SW so that it is editable later (which is really the benefit of SW) takes way longer than creating that same shape in Rhino.