Thanks for your detailed reply, MRFS. Comments below.
> I don't like WiFi networks
It's necessary for this application.
> Then, XCOPY will work by doing both READs and WRITEs ...
I need this to work with my backup s/w, Acronis, which recognizes network drives. I'll manually access the drive rarely.
The UEBO looks good on paper but almost all the negative comments (including the cons given by people who otherwise rate the device positively) indict the HDD in one way or another.
The Panasonic device looks like it's just an interface between your Android device and TV. There's no mention of what type of HDD, or how many, it can accommodate, or the capacity of an embedded one if it comes with one. I don't think it has one or can accept one.
The Synology box looks like it's close to what I'm looking for except there's a big fan on the back (http://i1.wp.com/www.chiploco.com/wp-content/uploads/2012/10/Synology_DiskStation_DS213air-3.jpg). My application won't permit any air circulation, so I think anything with a fan will be a no-go.
Finally, the LaCie (like the Seagate WIreless Plus I mentioned previously) is intended to be the router on the network, not an attachment to an existing network. The latter is what I need.
Thanks for your reply, Brian. This thing's going in a weatherproof box in the backyard. The only physical connection it will have is to AC. The ideal product, as I envision it, would be a single HDD with some sort of NAS stack and WIFi built-in. Without a fan. Doesn't seem that hard to me, but I guess there aren't many people out there with similar requirements, or someone would have built one.