The thing I like the most is the way, once you have specifically selected some music to play, it will continue to play other tracks in the same vein one your initial selections are finished.
I have mixed emotions about Roon and still haven't decided if it is a keeper. To me, the choice between Roon and other music management programs is about the user interface and the ease of finding the music you want. I know that's not the correct 'audiophile' answer, but I don't care. I'll start by saying that Roon sounds just fine, but I find it no different than what I heard via LMS. I previously used LMS (the Squeezebox management software) to manage my music - I'd used that for about 15 years.
I know nothing about Audirvana, but am now three-fourths the way through a month-long trial of Roon.