Summary: Got this little marvel for Christmas last year and I love it. Put a seagate 2tb and a WD green 2 tb and had no problems with either. I mainly use it for a DLNA server to watch movies all over the house from other computers, Xbox 360 and LaCie LACinema mini and it works like a charm even with multiple (4) simultaneous viewings. Configured the FTP server to use from outside and it works well too, although a bit complicated to configure.
Pros: Very cheap when on special. Supports 3 TB, pretty easy to use. Works well with all DLNA devices (mine anyways), can be modified with custom software (didnt use it)
Cons: Very long to transfer files to it. Does not restart after power failure.
Summary: There are fancier NAS enclosures around, but for the money, it's hard to beat the D-Link DNS line. In my rough tests, the DNS-325 came up about 2-3 times faster than the previous DNS-323, mainly courtesy of its faster processor. Drives from the DNS-323 popped right in and worked. I'm still waiting for the new firmware that will add support for 3TB drives, but it's already available in beta form (Oct. 2011), so I'm not worried.
Pros: reliable, inexpensive, standardized, third-party app support
Cons: could still be faster, 4 bays would be nicer
Summary: For sure must have! Easy to use, supports large hard drives and has another useful features which I don't use for now. Maybe later. All my pc's at home are able to get shared files from one place.
Pros: Amazing thing, keep all my backups and other data which I need in a safe place. 2 hdds in RAID 1 and I'm sure everything is saved.
Cons: Now it is cheaper then I bought it... I'm envying :)
Summary: Excellent value and a very good replacement for my USB drive plugged into my router's USB port. Cheap in every sense of the word. Word like a charm, took 30 minutes to set up and everything. Annoying seeing how cannot access one drive while the other one is being formatted - in Standard mode. Didn't try any of the "apps". I can reliably see it as a mapped drive and it is fine for now. No fancy features at this price.
Pros: cheap, reasonably fast, easy to use, excellent value for the money