It really depends what you want your NAS to do. Yes, there are more expensive boxes out there that do much more. I doubt Ford owners moan about Lamborghini's being much better.
The point is, some people don't want IP camera support, automated 24x7 illegal downloads of p*** and access to a lifetime's worth of photos from any destination on the planet.
Some people want a Network Attached Storage system, to store stuff, on the network. And at a cheap price. This is what the DNS-323 does. Yes, there are some bugs - most consumer electronics of this nature do (media streamers, NAS boxes, TVs, even cars - you name it) but I'm tired of reading how apparently cr*p this box is, because it's not something that it was ever designed to be. Whatsmore, with a little knowledge and effort, you can make this box do almost anything you want it to at almost zero risk.