There are two R2R DAP scheduled to launch in 2018, HiFiman R2R2000 is based on PCM1704U and L&P LP6 is based on AD5790, so they should receive the award right away, let's offer a big round of applause to these brands for the insanity award. From technical discussion purpose, The R-2R ladder DAC which is a binary-weighted DAC that uses a repeating cascaded structure of resistor values R and 2R. This improves the precision due to the relative ease of producing equal valued-matched resistors (or current sources). So R2R is not complicated if you can settle with 16bit only. But if you want higher resolution, the level of precision will increase exponentially. The AD5790 is rated at 20bit, and the PCM1704U is rated at 24bit (upt o 96kHz only). So is it really that attractive if we are limited to 20bit or 24bit, and then down convert all other signal before the actual DAC? In addition, DSD signal will need to convert to 20bit or 24bit PCM.