Yes, Roon itself is very nice and without the nonsense claims about impact on the sound, I’m quite happy to just leave it on one of my Synologys.
It’s not clear to me where the need for a faster system is driven as a function of the size of the library (I would think all the metadata is in a properly indexed database and so) but I have plenty of spare CPU capacity around already if I need it.
Thanks to everyone for the guidance and feedback - I really do appreciate it.
I’m pretty sure that you truly have no need of a Nucleus whatsoever.
The dealers nonsense about better sound is really just that… nonsense.
It’s appeal lies in its appliance like nature which is aimed at non techies or just simply those who can’t be bothered to deal with computer related stuff any more.
It sounds like you have both the hardware and the nonce to get the job done without a Nucleus in your system.
Now….enjoy the music!
I wouldn’t worry about it at first, but once you do spring for the Lifetime license that upgradeitis will probably catch up to you. Does it sound better? Theoretically…it’s possible. There certainly is less pathways to introduce noise and interference compared to a NAS. My ears are not hearing it. I upgraded from a QNAP NAS with adequate RAM and built a NUC/ROCK with an 8th Gen i5 in a fanless housing. Way cheaper than the Nucleus and the performance does not disappoint. Once you start running multiple zones and using DSP, you’re going to need the dedicated processing and more RAM. Now, doesn’t that “sound” better than a NAS?
Well, it took just a couple of minutes to download the package, manually install it on the NAS through the package manager, start it, and select my library.
If one wants to do a time vs money comparison, assuming one already has the prerequisite computer knowledge, it would have taken longer to order a nucleus online, open the box when it arrived, unpack it, check for damage, carry it up to the media room, plug it in, setup the network connection and so forth than it did to just throw it onto a machine already running in my basement 
Your dealer is full of $hi+. Please tell them we said so. Cancel your Nucleus+ order and get back to more interesting parts of this hobby. 
On the SSD question, Roon’s database is a bit messy. If you have a large library, you will find that you have tens or hundreds of thousands of little files and lots of random I/O. Roon’s performance will gradually tank if the database is not stored on SSD.
You sound more than capable to sort this out on your own, but don’t hesitate to ping us.
Please explain — what noise and interference can be created? We’re talking about “bits”, not analog voltages – you can’t interfere with bits (at least not unless you break the cable or short circuit something!)
I understand the possible need for more CPU cycles in this situation but that’s completely orthogonal to the issue of the (clearly nonsensical) claim made by my dealer that a Nucleus sounds better.
Ah - ok – that makes sense - though I’m surprised they don’t use a database (SQL, SQLite or whatever else makes sense) to optimize seeks so as to avoid a lot of physical head movement.
This horse has been beaten to death.
@David_Jameson, I don’t really understand why you are so hell-bent on believing the words of your dealer, but it doesn’t matter, because the original question has been answered many times over in this thread.
If you want to continue the discussion on this subject, we have very long threads on this matter. Let’s not infect more threads with the topic, which often goes toxic. You can start here if you are actually curious as to why some people argue “bits are bits” and others argue “there is more than bits”: