The 1892 is a very scarce coin but it is not quite as rare as the mintage or some overly enthusiastic cataloguers might lead one to believe. In terms of overall rarity, it is on a par with the 1879, 1880 and 1890 as well as such earlier issues as the 1855-1858 P-Mints, 1863, 1864, 1869 and 1870. Most 1892 Double Eagles are in EF or AU condition. Mint state specimens are known but they are rare. Choice and gem uncirculated examples are definitely in the very rare category; I have seen only two full MS-65 coins that I can recall.
The 1892 $20 is very scarce in Mint State, but not as rare as when David Akers wrote the blurb below. His assessment that most are in EF to AU condition remains correct today. On the higher end, Gems above MS64 are extremely rare. NGC reports four examples in MS66 and above, with the finest being a monster NGC MS68 (a coin that has never appear on the market to my knowledge). Also, NGC reports an MS67 example, which sold in 1999 for over $63,000; however, the price record belongs to an NGC MS66 that sold for $74,750 in 2010.
A very few examples of the 1892 $20 are Prooflike, one or two of which would be considered Deep Mirror Prooflike.