Primarily shooting a GH2, coming from a Nikon DSLR background. I most often shoot in Aperture Priority mode and with the Nikon equipment I found Auto ISO rather valuable since I could set the ISO limit as well as a minimum shutter speed. With the GH2 I can set only the ISO limit and the Panasonic literature states Auto ISO will be adjusted based upon the brightness of the subject/scene. I interpret this to mean the ISO will be boosted to achieve a proper exposure as the camera's meter sees fit. Intelligent ISO is said to adjust the ISO value according to subject brightness and movement. I enjoy shooting general nature shots while exploring the natural world and I like to photograph dogs in action. I'm using the Panasonic 100-300mm much of the time and my results are getting better. I'd be most interested in hearing how the two Auto ISO settings have worked for others, which you prefer, or if you simply recommend avoiding this feature all together. Panasonic's explanation of its implementation is a bit vague and often user reports from the real world reveal valuable insights. Thank you.