It's the difference between SDL and OpenGL for rendering on a PC. One can be used to develop graphics based applications quickly, but its power is limited, but OpenGL is more complicated yelider higher results.
To a point SDL will out power OpenGL because of simplicity (XBox 360), but once someone really puts OpenGL (PS3) to good use most will never look back.
*I am in no way stating that SDL and OpenGL are actually utilized in development for these systems I am using them as metaphors to describe how philiosophy has left one medium under utlitlized simply because its more difficult to use.
-- Nothing is nicer than seeing your PS3 on an HDTV through an HDMI cable for the first time.