From my personal experience with Synology, the software is awesome, but don’t cheap out on the box you buy.
I bought the single drive unit and intended to use it as a location to stream from to my Chromecasts. The CPU in it simply wasn’t strong enough to have data copied to it, and be accessed at the same time. If you were streaming music from it whilst accessing it on another machine, the music playback would be choppy.
Now, this isn’t an issue if you just want to use it as a storage location on your network, but generally, NAS boxes have a host of features which are difficult to ignore, because they work very well (assuming, the CPU isn’t too weak, as pointed out a moment ago.) The Synology boxes allow you to store your data and also, they will work with certain software to transcode video to devices such as Chromecasts. You can use them with IP cameras to run as NVRs, too. They basically are a PC without monitor or keyboard/mouse connections, so the configuration is done by browsing to the boxes in built webpage. People do rate the Synology boxes and the software support for automated backups, but I never got that far with my one because it just wasn’t suitable for the purpose.
Backing up is key, and as long as you have a copy of what you do not want to lose on a different device from what you use on a daily basis, that is a good start. I have 2 2TB drives in each of the main PCs at home, one being the HTPC/Server box which also doubles up as a CCTV server, the other being my main porn viewer/gaming rig. All my data is the same on both PCs and I choose to manually copy everything to both locations whenever I rip a CD or I need to process photographs from memory cards.
Because I am proficient in building/running/maintaining PCs, I didn’t bother trying a bigger, more powerful NAS box, because it literally is a PC with 1 or more hard drives in it. Once you add a hard drive to a PC, whether it is an external USB one or an internal SATA connected drive and share it, it is a NAS box.
If you have a spare PC laying around and you have the means to have it connected to the network, that is the route I always recommend. Having a single large enough storage device is far more convenient than having several pocket hard drives. I can’t recommend any software to install on other PCs which would take the data from nominated directories and back it up to the NAS box automatically because I don’t use it. If you go that route, I cannot emphasise enough that it is up to you to check manually periodically that your important data is being backed up. I have been let down by automated solutions in the past, so I choose to spend an extra minute or 2 copying stuff to my “backup” locations manually.
I said earlier about a NAS box being a PC without a monitor or keyboard socket on the back. If you use a conventional PC, you will have monitor and keyboard sockets, meaning if something isn’t working, you can just plug in a monitor and check that the data is there, which is important if the NAS drive has a network connectivity issue meaning you can’t access it.
An ordinary hard drive can be bought for £50 and installed in a PC with ease, sharing the drive over the network isn’t difficult.
A waffly post, I apologise for that, but making sure your data is safe/accessible is more important to me than having everything automated and I always wish to point out to people that a “NAS” box which costs a few hundred is not the only way to have success.
EDIT: Forgot to add, on my server/NAS pc, I have logitech media server installed for music play back on the Chromecasts, along with the “Videostream” add on to the Chrome browser for video transcoding to the HDMI Chromecasts around the house. Both give me a library which can be accessed/browsed on mobile apps and I’ve not yet had any issue with either of these features in the year since I set the system up.