I recently bought the NAS200 from Linksys as a backup device for my workstation in the office. It came as a very highly rated NAS so I chose this one.
The packaging is what you come to expect from Linksys and a neatly packaged software CD for which I only used the driver. The device itself is incredibly easy to setup, unpack the device open the drive bays and literally just slide in the drives one by one, plus in the power and LAN and its ready to go.
One detected and the drivers where installed I realized that you HAVE to format the drives using the Linksys format (Linux based) before the drives are accessible. I found this a little disheartening at first but after doing some research I decided its not that big a deal to me.
The device once installed was easy to map a network drive and setup my backup tools to backup to the drive. I personally use syncBack instead of the one button as I have somewhat complex backups from multiple drives and folders. The one major drawback I found is that I only get a max transfer rate of 2MB/Second so the initial backup took a few days (over 300GB) of information. Once that was completed though backups are quick and the system is very quiet. In the admin settings of the NAS you can set the auto spool down interval of the drives and it works so well. As soon as the device detects an access via LAN the drives spool up and you have access in a second or two.
Overall I would recommend the NAS200 from linksys to anyone looking for a multiple drive NAS backup system that is small enough to sit on the desk and quiet enough to not make you turn up your speakers to try and drown in out.