I have been a Roon user for a few years and my last upgrade was to purchase a Roon Nucleus Plus, which I highly recommend. They also sell a Roon Nucleus, but I decided to opt for the Plus model (faster processor, more memory). The only "downside" is that it only has USB ports; if your DAC sounds its best with the USB input (as mine does), you should be "good", but if you need a coax or optical feed to the DAC, the Roon Nucleus or Nucleus plus would not be an option for you.
If you are good with doing your own installs, you might opt for an Intel NUC and do your own install of the Roon core...a lot less money than the Roon branded NUC.
If you are good with doing your own installs, you might opt for an Intel NUC and do your own install of the Roon core...a lot less money than the Roon branded NUC.