Alegria
As an alternative to your choices above, have you considered a Linux box (regardless of flavor)? Great for recycling an older computer you don't use, easy to set up within your existing network (wired and/or wifi) and in my experience, very reliable.
We don't have any desktops on the network so the obvious choice of using a big shared drive on a desktop isn't a immediate option.
I was reading about FreeNAS and considering the possibility of using an old video edit desktop box as a dedicated server, but I am attracted to the very small foot print of a dedicated NAS of some sort.
The reason I have become interested in the Seagate Black Armor is that the hard drives can be replaced etc.
I have also considered that the price of a Seagate Black Armor is less than half of what I'd have to pay to build a DIY NAS assembled out of similar drives.
It seems like it, or something with that form factor, might be an effective stepping stone as my needs evolve.
Right now we use two external drives for our photos. One mirrors the other. My wife and I photograph as a hobby, so there are a lot of photos... more than fit on our laptops, and external hard drives are beginning to seem like a hassle.
The goal is too end up with one of those drive spaces on our wireless network so we can get to the photos with our laptops more conveniently via wireless, and then continue having another space as a back up.
best regards,
mike