How good is the RX100 Lens?

"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)."