I took a series of photos at the base ISO 80 and also at remarkably high ISO 1600. The full-size images at the base ISO setting were very 'clean' having hardly any visible noise. At ISO 1600, there was some detail loss due to the noise-reduction process with acceptable noise, therefore the images at this high ISO are still quite usable.
When the images are reduced to the size I am posting up here, you can hardly see the difference between the images. The colour rendering and the dynamic range are also quite impressive for a camera that fits into the chest pocket of a shirt.