Regarding the ‘new world’, a few years ago my CD player was on the blink, so as I do at such times I turned to the HiFi press to find out what was around, and learnt of this new (to me) streaming world. It seemed to me that streaming is the medium of the future, so made more sense than investing in CD, which I would expect to lock me in for another 10 years. After due research I got an ND5XS, and bought a cheap NAS (Zyxel NSA325) to store and serve. (Ialready had a home network). I had a head start with music files as just a few years earlier I had decided to end my vinyl playing days, and had ripped all my LPs, creating CDs - but I had kept the original ripped files on a hard disk as backup, so a quick transfer of those to the NAS gave me a few hundred albums for starters, while I set about ripping all my CDs.
Although bought unheard due to where I live, I was pleased to find that sound quality wise the ND5XS was very similar to my old CD player (Shearne Phase 7), so I was happy (I had not been seeking an uplift because I was content with the sound of the Shearne).
Once all my CDs were ripped I never looked back - streaming from my own store was so easy and convenient, with an added benefit of no more shelves of disks required in the listening room. And it opened up a world of buying and downloading online, with the potential for higher sound quality with higher resolutions (I say potential, because they do not all necessarily sound better, but that is another subject). And no more mechanical CD mechanism to start to deteriorate and eventually give tracking problems, or Cd defects, causing misreading and error correction with a potential reduction in sound quality.
One additional thing you can do with at least some streamers, if not all, is access online music streaming services. There are subscription services that are said to give the same sound quality as your own local store (e.g. Qobuz and Tidal), and free ones with lower sound quality and adverts (e.g. Spotify). Some people think that approach is better than own collection because of the huge choice, others prefer the security and absence of subscription of their own store, and many people mix both. (I don’t subscribe to any, but I find the likes of Spotify invaluable for checking out new music to decide if I want to buy).
One word of caution - if you do go the streaming route, be aware that the metadata embedded in music files can be crucial to the streaming library software, and diligence in checking and if necessary amending or adding right from the start of ripping or downloading will save a lot of heartache later - done on the fly it is a minimal consideration. This is not something to worry about as such, I am just mentioning so you have in the back of your mind to look into if/when you to do commit to it.
Of course, as with any hifi, you can end up on an upgrade path, and Naim have fairly clearly identified patha and hierarchies. And of course there is not just Naim, many people finding that the Chord Hugo family of DACs are beneficial used with Naim streamers such as ND5XS and NDX in place of the internal DACs - some on this forum about that, though much more on the old forum. In my own case I tried a power supply, was disappointed and instead did the Hugo thing, to great effect, later replacing the ND5XS front end as well… but that is another story!