I have the original BeagleBone white, which is similar but twice as expensive as the black (they are very similar but with slightly different builtin peripherals). The BB may work great as a server, but is lousy as a player. The USB implementation on these TI ARM chips leaves out of the hardware some important parts of the functionality which have to be implemented in software. When trying to run high speed with a continuous stream (such as UAC2 audio), the poor processor can't keep up and you get clicks and pops.
The BB really shines at low level peripheral connections, it has rows of connectors which contain the low level interfaces to the processor. AND the software contains drivers to talk to those pins! This makes it really easy to talk SPI, or I2C or do direct PWM etc etc. It's more a DIY dream come true than anything else.
John S.