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.
It’s only limiting if you’re doing things that need more RAM and faster drive speeds (most people are not). Of course, if you need more, don’t buy this thing? I didn’t say it was great for EVERYBODY.