If you can properly control temperatures passively then fanless is ideal. Audible noise will not be a concern, but fans do produce vibrations and EMI. There is something to be said about keeping components cool, and active cooling can counteract the drawbacks of spinning fans. High TDP processors and real time upsampling can generate a lot of heat that no amount of passive cooling will dissipate.
A NUC serving native files will have no problem being passively cooled.