I think this is the best DAP for listening to 44.1k, 16-bit music files. The R-2R DAC creates a wide, deep encompassing soundstage, that my Fiio M11 Plus did not. The Fiio DAP is a great unit, but the HIBY RS6 sounds much better overall!
The operating instruction suck, but once you learn to swipe UP, DOWN, LEFT, and RIGHT one can find the menus you need to setup the device to your preferences.
To perform a Firmware update, swipe UP from the Home screen, choose Settings, then System, then update system! Firmware version 1.7 is the most current, so you may need to update several times, I had to update from version 1.2 to the current version.
I highly recommend this DAP, it is worth the price!