I had the 100 and the output was fantastic, but the ergonomics were horrible. I put up with it for image quality but when the 100S was announced I knew I had to change. I quickly sold the 100 on ebay, netting enough to pay for the 100s. It is everything I hoped for. Same images with awesome ergonomics. Fits in my hand perfectly, doesn’t burden my aging spine, buttons and dials are much better. My only complaint is that the exp comp button, while better, is still awkward to use. I though I would have wanted a dedicated SS dial but since I shoot mostly aperture priority it’s not a problem.