My Seagate Centel 2TB NAs died just over 2 week ago and have been looking around for a suitable replacement. Synology, although a little bit more expsensive, seem to be a better replacement what I had. I like the fact you can add your own Drives in and if the they fail, you can simply swap them (or pop them in RAID so you can restore a backup).
I kbow this isnt the cheapest it has been but it is the cheapest I can find for a decent Unit. I didnt want to more than £150 on one and the specs on this seems perfect.
Update: Just did a Flubit and got an Offer for £127.17 which isnt too bad