time capsule

Better Half and I have been using FreeNAS for a little while now, and our one month report continues to hold true – it works, it works well, and it works transparently, and as long as you can get through the installation process (which can be more difficuilt for some folks than others), you have yourself a solid piece of NAS software.
Unfortunately, the hardware is not holding up its end of the deal. In this case, we installed FreeNAS on an 8-9-year-old Sony COTS desktop, that has been occasionally tweaked and upgraded by me over the years – predominantly, a newer (and now wasted) video card and more RAM. After stuffing every old IDE hard drive we had in it, it weighed in at just over .5TB of backup space, which is sufficing for our purposes… for the time – owning a DSLR makes one’s “Pictures” directory grow quickly.
However, those hard drives are easily as old as the computer itself and are likely not far from their eventual deaths, the computer is getting increasingly noisy (a combination of fans and hard drives), and I shudder to think of how much wattage it is sucking on a daily basis, what with its 24/7 uptime. So, what are the alternatives?
On the one hand, we can simply get a 1-2TB external ethernet-capable hard drive, plug it into my router, and be done with it. Its footprint is small, its power consumption minimal, and in terms of “grab-and-go” emergencies, that is about as easy as it gets. However, expandability is non-existant, and when (not if) we surpass that amount of storage space, we will have to get another one, adding to the clutter/load/etc.
On the other hand, we can replace the current computer with another computer, kitbashed out of the new power-sipping Atom processors, “green” hard drives, and another install of FreeNAS. This requires not a small amount of attention paid to the hardware and whether or not it is supported, less power than the current desktop but probably more power than a pre-built NAS solution, an end result that will never be anything more than a NAS (FreeNAS cannot be dual booted), and a product whose future is getting interesting.
And on the third hand, we can procure a pre-built NAS solution, of which there seems to be no shortage, including increasingly-interesting Windows Home Servers.
So what do you, my readers, think? All of the computers in the house are Windows-based, with the exclusion of the XBoxes and TiVos, which can all talk through my desktop anywise, so compatibility from that front is not a significant problem. We are not big on streaming media and such, and have only used our NAS as a scheduled-back-up repository. We do want something that uses minimal amounts of power, uses multiple drives with some form of data redundancy between them, can be expandable, internally, when we can afford to do so, and can be gathered up and carried off without too much heft, trouble, or concern, should the situation call for it.
After doing a little more research on Windows Home Server, how Drive Extender compares to RAID (naturally, the M$ geeks fall on one side of the fence), how things fit together, and how modifiable it is, I am currently leaning towards the Acer Aspire easyStore AH340 (in-depth review here and here (though both are slightly outdated)), though that is, of course, subject to change.
So, what say you, my readers? Stick with a drive that is nothing more than a drive, build my own plain-and-potentially-complicated NAS, or go the COTS route with all of its bells and whistles?