Ive been using netgear pro duo 2 for about 18months and its been EXCELLENT.
Ive had other nas boxes in the past but this one has the X-Raid which is a breath of fresh air in comparison to other setups.
The X-Raid is automatic, you start of with one hhd and it wont be backed up, as soon as you add more it will automatically restripe the drives and expand the storage whilst still in use, my old nas if i wanted more storage i had to remove the drive back it up then reformat them to add the drives, taking my storage of line for days at a time.
ALSO
if your getting any drives look at the WD reds with nas ware.
I have one in my setup (segate failed after 14 months). The wd reds are slightly more expensive than standard drives but they have a 3 year warrenty, and they consume less power, make less noise. The temp it runs at is a lot lower, under load my standard seagates hit about 44-50 degrees, but the wd red never goes above 29 even under very heavy loads.
Heres a screen shot, you will see the wd on the bottom
btw with 4x 3tb drives im getting 8.1tb of storage with x-raid so approx 1/3 more space than i had on my last mirrored array
