Regrettably, the real weakness of the Sony RX100 is the lens resolution— it’s pretty lousy at most settings, woefully underperforming the sensor in many situations; the sensor is in my view a breakthrough tour de force given its size and resolution— the density maps to a 147-megapixel DSLR if scaled to DSLR size. See Sensor Photosite Density on the Sony Cybershot DSC-RX100.
Yet the RX100 delivers frustratingly poor results in many (too many) situations; this is not a sensor issue but a lens performance issue— it a very, very poor performer at many if not most zoom settings and distances. As in maybe 1/3 or 1/2 the rated resolution (e.g., 8-12 megapixels from a 20MP sensor). I’ll be showing this my review. So long as one accepts that it is only (rarely) a 20-megapixel camera using those 20 megapixels for oversampling, and that producing 8-12 megapixel results with low noise and good detail should be the goal, then pixel performance sanity can be preserved.
The image below shows the RX100 at its best. It is from RAW is at ISO 125 with a push of 0.4 stops for an equivalent ISO of ~180. The noise is very low, the detail is very high— this is BY FAR the best image quality I have ever seen from a camera of this size. And kudos to Sony for including RAW.