Pros: I got a ReadyNAS because it's the only NAS box that can run the Logitech SqueezeServer music streaming server natively... saving me having to get a whole system or leave one running all the time. If you want to do the same thing get atleast the Ultra 2 like I did as everyone on the Logitech forums says the Duo is too slow. Besides for about $70 over the price of a Duo you get 4x the memory and 5x the processor speed... why wouldn't you. So what's good? Quick and super easy setup, silent operation, can connect a usb printer to your network, backup software included, can connect more drives via usb, supports nfs in addition to more common protocols, can be configured to power down at certain hours, will automatically scrub disks, you can get shell access to the actual system. Unobtrusive size too. For the future if you want to upgrade the size you just have to remove one drive and replace with a bigger one. wait for it to sync and then replace the second... couldn't be easier.

Cons: Make sure you check the hardware compatability list before buying your drives or you won't be supported. I got 2TB Western Digital Caviar Greens since I wanted low power and quiet. These certainly aren't the fastest drives out there but to sync the mirroring took 6hrs.