I've been running a full tower Windows server with a dozen drives for a decade and decided to downsize. This ministack does everything I need at a fraction of the power, noise, and heat.
I use it primarily for Plex but also host a few games servers for buddies. It fits perfectly in my entertainment center.
Spent around $200 on the Mac Mini plus $600 on the drives and enclosures. I'm using SoftRAID for RAID1.
But also recoding hundreds of movies you will never potentially watch is a waste of power. (I'm assuming a single user setup where stuff is only watched once in a lifetime in most cases)