This is my second PR4100. I have had a good experience with the first for the last 3 years so I purchased a second after looking at alternatives. WD was able to deliver in 4 days and I stuffed the NAS with 14TB drives run in a Raid 5 configuration. This second PR4100 is essentially a backup of the first. Both NAS systems contain plex media and backup of the family PC data. I have both systems on the same UPS and make use of the network UPS option. Syncing of the systems is done with Resilio Sync.
Bought this a couple of years ago. Mainly because of the WD Sync feature which is now longer supported. Disappointing that another business is heading down the path of having to pay for features annually. Great product, but useless without the right software to do what you need to do.