Seconding what Ged said!
Lots of people run Roon as an all in one box. Whether or not it makes a SQ difference is really up to the individual user, their environment and even the specific equipment being used.
I run the RoonCore on a multipurpose machine in my basement. It serves the rest of the house remotely, but, I also use it as an all in one (core, control and output) when I sit next to it in the downstairs office. Take a peak. Sounds great, especially though the EVGA NU Audio Card.