Synology's DS718+ NAS DiskStation (Amazon) is $400 data storage box. For me, it replaces very two annoying things: a monthly subscription to Dropbox, and a drawerful of USB drives used to back up a houseful of computers.
But file syncing and backups are just two things a modern NAS can do.
In fact, the first thing you'll notice after setting it up is that it's really a fully-featured computer that happens to be set up with storage in mind. The web-based control panel replicates a desktop user environment, complete with windows, folders, icons and drop-down menus.
There are pros and cons to this. One one hand, you'll not only get rid of cloud subscriptions, recover your data privacy and have less gear lying around, but find yourself with a hundred other interesting applications to fool around with. Want a basic web-development box? There's one-click setups for Apache, nginx, common databases and popular platforms such as WordPress, Discourse and Node. Want to use it as a 4K media streaming box? Easy. Want a fancy-pants router? It has dual gigabit ethernet and can be set up as to provide DHCP or VPN.
On the other hand, it's more complicated than the things it replaces. I just wanted to get out of the cloud and get rid of all these damned backup drives, but now I'm a sysadmin. (There are less fancy options such as WD's My Cloud devices, but they're almost as expensive (Amazon) when the cost of drives is factored in)
And I'll admit that I enjoyed experimenting with Synology's add-ons. If you live in the future, you can automate your house with it. If you live in the past, you can serve your own e-mail. See the full list. Setup was easy, about as hard as a networked printer. Adding app packages worked without fail—I've never had such an easy time getting a basic LAMP stack up and running.
For computers and phones, Synology puts out a panoply of single-purpose applications that each hooks into a specific NAS feature. There's the drop-in Dropbox client replacement, Cloud Station Drive. There's an incrementing file backup app (though I just used Time Machine and File History). There's a media player app. There are so many Synology apps that it can be hard to tell exactly which one you need for any given purpose, but I prefer this discrete approach to the thought of there being one giant bloated "Synology iTunes", especially on mobiles.
You can set up an account with Synology to access a NAS remotely; the alternative is configuring port forwarding rules in your router. Synology's service trades privacy and speed (transfers are routed via their own servers) for user-friendliness. Not my cup of tea, but if you're getting grandma a NAS for Christmas, likely essential.
My biggest problem was something I'm sure wasn't its fault: initial full-system backups are excruciatingly slow over WiFi, and it's multiplied by the number of laptops you're hooking up to it. After that's done, though, the regular incremental backups (using Time Machine) roll by fast enough not to be noticed and have never failed.
The model tested has two bays for redundancy, 2GB of RAM and 1.5 Ghz CPU. Single-drive Synology models start at about $200, if you like living dangerously and slowly.
For dumb consumers like me, servers and services should be unseen things that you never get bothered by or even have to think about after initial setup. And that's exactly what I got with the perfectly boring and capable Synology NAS — at least so long as I don't think about all those features and that remote desktop thinger and the notifications bar in it bleating about updates. Bye bye Dropbox! Bye bye dangling backup drives! Hello modicum of privacy in the fading light of civilization's dusk before the annihilation begins!
DS718+ NAS DiskStation [Amazon]