Many people think it is just easier to superimpose in PS and will give the same result
Multiple exposures through the camera or superimpose in Photoshop are not the same.
When you make a double exposure in the camera best results are when working with a dark background.
When superimposing through Photoshop it is just the other way...The second image will be visible only through a light background.
Made a test both ways..
One is made in the Camera, the other one were two exposures superimposed in CS3.
However close, note the highlights..up to you which image was made directly in the camera.