ISO-bracketing and HDR

I've noticed that the E-3 got ISO-bracketing. To me it sounds like this should be an easy way to create an HDR-image. I know I can make a HDR-image after making 3 or more exposures, but that will require a tripod. When using ISO-bracketing with the E-3 I only need to make one shot, and the camera makes 3 or 5 images with different ISO and different exposures. The shutter speed and the aperture stays the same.
Have anybody tested this? Too good to be true?
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Bjoernar