All the below NAS's are spec'd as 2TB, (2x 1TB?). What is preventing you from sticking in say 2x 1.5TB drives taking the capacity to 3TB? Or even 2x2TB drives? Netgear RND-2000 QNAP TS-209 Pro D-link DNS-323 Has anyone tried this? What do you think would be the implications? I dont want to buy a NAS with only 2x drive bays and then have to upgrade the whole unit in the future as I need more space?