Metadata
I think that for Roon there were many changes under the hood in their metadata cloud over the last months as many new sources got added (Tidal, Qobuz, MusicBrainz, …). As metadata is treated/stored/delivered in different ways from different sources, there was no possibility to do a simple field matching to integrate those new sources. A much more improved and clever way to match the data from different sources was needed. I also think that Valence has emerged from this efforts. But at the end of the day there’s still no way to display (additional) metadata for content were no (additional) metadata is available from the – available to Roon – third party metadata providers.
As already mentioned in another thread, the additional metadata (metadata beyond the basic set of album/track titles, performers, …) is mostly not understandable by a vast majority of potential Roon customers anyway because it’s availability in English only but this is not a problem per se, as those potential customers will either not get any additional metadata at all or the same English only metadata, no matter what player they choose in the end.
Library Management
What’s a users definition of library management?
As Roon never touches your files, you end up with the same files in your library that you started with should you choose to stop using Roon and as far as streaming content is concerned, it’s just gone. No tags or playlist created in Roon reflect to files and/or streaming providers. Is that management?
RAAT vs. UPnP/DLNA
RAAT looks to me like a technically superior way (over UPnP/DLNA) to stream audio content to endpoints. It’s one of the reasons why one – even the non English speaking one – would might want to use Roon.
That RAAT then fails to deliver with products of major brands (NAD/Bluesound, KEF, …) is a pity.