I have to admit, a bit of digging into this and I start seeing the plus sides to one, and the likewise the minus to the other. In looking for a really robust solution, Raid 10, or 1 + 0, seems the way to go, but man does it eat the drive space, and I always lean to the side of cautiion, to much so perhaps. This gives me a new appreciation of the decisions going into configuring the big stuff, and why the hot swap is so attractive. Also this makes my raid 1 with the x-copy to the external solution continue to look attractive, well as a cheap alternative anyway. At first blush, I hadn't considered the power side of building one from recently retired parts , pretty bad since I have to deal with poor power managment alot. Regardless, it makes sense that a purpose driven NAS will be much more power efficent, and in the long haul, most likely represent the best choice. You've got my attention for sure there Tom