A couple weeks ago I purchased a Synology 412+ with two 2 TB Western Digital Red drives. I’ve been using it as an additional backup location for my computer as well as a media center. I added a CyberPower CP1000PFCLCD 600W UPS in case the power goes out temporarily. It has been working perfectly. It is running Synology Hybrid Raid, which, with only two drives, is equivalent to a RAID1. I have yet to add an additional drive (waiting until prices drop), at which point it will be a RAID5 NAS. I don’t know if it is the NAS or the drives, which are designed for NAS use, but this thing is super quiet; I can’t even tell that it is running even when it is being fully used.
Rather than recap what many people have already written, I’ll just link to a few reviews of the 412+ that I found: