I needed an all-in-one HTPC and storage system (NAS) that will be on 24/7 and accessible within my local network at home. I looked into pre-built individual systems such as Synology, QNAP, etc., but they were too pricey even for a 4-bay system (over $300). For that money, it was better to build my own 8-bay PC system with much more power and customization.
I had originally looked into a mini-ITX build with the SilverStone DS380B (8-bay hot-swappable) and ECC RAM, but it was a bit over my budget. Perhaps for my future builds when I needed something more portable. The LGA 1150 micro-ATX platform was highly available and cheap, and I found a good deal on the ASRock H97M Pro4. I went with the G3258 for its low-cost raw power and 53W TDP. The 16GB RAM was plentiful for what I need, which I planned to run Kodi (XMBC), Plex, JRiver, etc. on Windows 10. The Fractal Design Define R5 case was the perfect housing to fit everything in, including the 8-10 3.5" HDD & 2 2.5" drives--it's a little big for that micro-ATX motherboard :D.
For the redundancy or resilience setup for my storage, I have tried Windows 10's Storage Spaces to no success. I have tried two-way mirror and parity, and found that parity was a lot slower with 40-50 MB/s write, as compared to 100 MB/s write. Storage Spaces's setup was pretty straightforward, but the data recovery is painful from reviews I've read online. Also, I did not like the idea where I cannot simply unplug a drive and put it on another PC to transfer. I went with SteadyBit's DrivePool, which was a lot easier to setup and run. So far so good.
Overall, I am extremely happy with the setup. With 3 x 5TB WD green/blue drives running on idle, my Kill-a-Watt meter was at 25-30W. At full power, it is roughly at 50-60W. I imagine topping at 100W with a full rack of 10 drives.