Noise, low ISO sensitivities

Even at ISO 160 (the GX1's lowest), shadow areas still display the blue-channel artifacts that tend to plague Panasonic's JPEGs, appearing as yellow blotches--look at the text on the left side. (It's a lot easier to see the problem if your monitor is calibrated to Adobe RGB rather than sRGB.) Processing raw files makes a big differences in clarity even at this low a sensitivity.