I tested beta version of RuneOS (RuneAudio_Pi_0.1-beta_2G.img):
Hardware: Raspberry Pi B version, old model with 256MBy of RAM
On usb I have: 24bit /192KHz CM6631A USB to SPDIF
SPDIF out then connected on "Hi end DAC 24 BIT 192K HZ AK4396" kit board.
I must change sound output in mpd.conf:
device "hw:1,1" << Default is set hw:1,0
After this minor change I have success.
Sound is good, without crackling and interruption, tested FLACs on 44.1kHz and 96kHz 24bit.
Use NAS based on linux Ubuntu, without any trouble.
Note: If NAS don't have username/password, I must set something in username field.
In comparing of RaspyFi I think that this webUI is more agile and have faster response.