Over the years I've discovered that my preference isn't for one system but for multiple systems. I've got a pretty careful and elaborate backup routine, so my fear isn't so much of losing data permanently as having it become temporarily unavailable.
A year or so back I was given a Dell the original user got frustrated with (or, more accurately, she got frustrated with W*nd*ws). I maxed out its RAM with 16 gigs, pulled the original hard drive, put in a 1TB SSD and installed what was then FreeNAS but is now TrueNAS.
TrueNAS is free and loaded with features, certainly more than I'll ever use. But if you just want a reliable, expandable server with the robust data protection you get with the ZFS file system, you can ignore all the fancy stuff.
In my current setup, the internal SSD is used as a scratch drive that all my computers can access. When I digitize analog sources, I wind up using a combination of W*d*ws and Linux tools, so having the data located where any computer can process it is a must.
In addition to that, I have four external USB 3 drives. If blazing fast speed is important to you, you can probably stop reading right here. Personally, I'm less concerned about speed than I am about reliability, budget and ease of expansion, so USB 3 is fine with me.
Those four drives are in reality two different mirrors with two different sets of data. One pair is just for music that can be played on a Squeezebox (PCM stereo, DSD stereo, AC-3, DTS). The other is for multichannel DSD and multichannel FLAC that plays on other hardware. It also stores all of my HD-DVD collection that I was able to rip before the discs rotted.
As with RAID, in theory anything I write to either of those shares winds up getting written to two identical disks. If one fails, it's a very simple operation to replace it, during which time your data is still available. It's also very simple to add another mirror at any time. In fact, both of those shares originally started as single drives that had mirrors added later.
But, RAID is *not* backup, so those primary drives are backed up to a combination of cheap standalone WD single-disk NASes and USB drives connected to other Linux boxes. I've found the latest Raspberry Pi 4 to be a perfectly acceptable server to host the backups.
The advantage to a hybrid system like that is ease of cutover should the primary box fail. Hopefully that won't happen any time soon, but if it does, all I have to do is re-map the client machines to access the backups instead of the primaries.
In the case of my normal Squeezebox music, I keep the mirrored drives on TrueNAS, a copy on a USB drive connected to the Pi and two copies on two different single-disk standalone WD NASes. It's also backed up to a server in France and another in Norway. It took me 18 months to rip all my CDs, so I am heavily, heavily motivated to take backing up seriously.
My experience with the cheap single-drive WD NAS boxes is that they're great until suddenly they aren't. Specifically, I've had AT LEAST three of them get bricked when I obediently attempted to update the firmware after much nagging. They seemed to go through the update process, then never, ever booted again. In every case, I was able to remove the hard drives, put them in a USB enclosure and use them elsewhere. One of the drives does show in TrueNAS as having 264 uncorrectable sectors, though that count has never changed since I started using it. The other two drives are allegedly completely free of errors, so the fault was somewhere in WD's software. I still have two of their boxes that are begging me to upgrade, but I'm not falling for that again.
Anyway, this is all my typically long-winded way of saying that rather than committing to a single brand or approach, it's probably safer to use a mix of hardware and software. Hopefully everything won't fail at once and if/when anything does, recovery will be relatively simple.
If anyone is tempted to try to roll their own NAS, I'd suggest getting a Raspberry Pi 4 with 8 gigs (probably overkill, but better too much than too little) and one or more USB 3 drives. That's a cheap way to get started and figure out quickly if that approach is right for you. If not, the Pi can be used for a whole bunch of other things, including as a Squeezebox player or, with Kodi, a multichannel player.
