I'd agree, if you're happy with using your PC, then there's no reason for a Nucleus. The reasons for looking at a stand-alone server might be that you don't want to leave your PC on, or don't want to be prevented from rebooting it when someone is listening to music.

There is also the argument about potentially better sound quality from a purpose-built machine, but I won't head down that path today!

Prolific music listener / Hi-Fi addict!