I have a DL4100 that I am backing up via WD’s remote backup to my PR4100 (located on my LAN).
When I use WD’s encryption option to do the backup, I achieve about 35MB/s data transfer speeds.
When I do not use the WD encryption option, I achieve about 75-80 MB/s data transfer speeds.
That represents hours saved when backing up TBs of data.
I believe the 75-80 MB/s rate also shows that I am achieving the advantage of my Gigabit Ethernet LAN.