I see absolutely no difference with my 1200 dpi mouse. With cursor disabled i get the same as when it is enabled with various settings of dpi (tested with 400 dpi, 800 dpi and 1200 dpi)
My mouse settings are as follows: The pointer speed in windows is set to neutral (the middle bar) and i have acceleration off.
So basically i guess all the raw input does is take away the mouse accel and the pointer speed set in the settings.