I have PLEX Media Server running on my desktop now... when the PC is in sleep mode I can't access it from my mobile devices. It won't "wake up" the PC.
Well, okay, I'll confess to having one old Panasonic Toughbook on 24/7 hooked up to my network.
I use that LogMeIn software that allows you to wake up any PC wired to the network using any Android or iOS, even in Shutdown mode, not just Sleep.
The Toughbook is kind of a sacrificial lamb. Hey, they don't call them tough for nothing.
So then I can remotely controll all PCs wired to my network anytime anywhere - Shut down, Power up, Sleep, Wake, etc.
But having the NAS on 24/7 is the norm. I'm just NOT normal.
I actually have fifteen 2TB HDDs (30TB) on my NAS PC, 6TB on one HTPC, and 6TB on my 2nd HTPC.