Where to put the encoder PC. With the storage or with the players?

Question for you guys: I'm building a small form factor PC to be a dedicated Plex PC so I can start powering down my workstation (it's a big power sucker).

My media files are on my NAS. My network for my NAS topology goes: Modem > Router > unmanaged Gbe switch > Twin Cat6 to a link aggregated port on my NAS.

Now, where should my PC go? Should it be on the switch with my NAS.

OR, should it be on the wireless media bridge with my wired content players (PS3, Amazon TV)?

My friend suggests the latter: "wireless data transfer will always be cleaner than wireless media streaming"

What say you?

Also, what would work better for off network access (via phone, tablet, etc...)