I'm of the "my NAS/home server is an old Laptop and a bunch of more or less random drives in a box" persuasion, but this is great work and great documentation! :)
The solution works really well though - a reliable, name-brand SSD (sic) in an old $100 Dell Latitude as the workhorse. The Latitudes allow changing the charging profile in BIOS to "always plugged in" amongst the other power friendly things (disable TurboBoost, etc.). Built in UPS, keyboard, monitor, wifi/eth; portable, quiet and with the right tuning (disabling a lot of modules in GRUB or module blacklists) runs most of the time without kicking the fan on. I run 2, one doing all the work and another backing it up. I run with only a partition encrypted (requires manual unlock after boot, my choice) so that I can remote login after boot to mount that, never have to actually open the laptop unless, say, wifi goes south. Laptop dies (they never do), just pull the SSD and slap in another one it's Linux it'll boot.
I agree, especially about the integrated USP and peripherals.
In my case, I currently use a Macbook Air M1 (my personal one which I currently don't need as a laptop). Absolute overkill and in some aspects annoying - only two USB-C ports for example - but it was available and it's fanless and doesn't need much power.
Just a random powered USB-C Hub with a few external drives on one port and a Thunderbolt SSD I had from an old project on the other.
For now, I just use the SMB server built into MacOS because I've not gotten around to installing Asahi on it.
I think I turned auto update off on this machine but if it reboots, you would have to login first. Doesn't bother me, though. I don't have any uptime requirements.
Depends on what you need or want to do with it, I guess. Storage via USB-C or Thunderbolt and Ethernet over an adaptor works fine and is plenty fast for my music and video library and as a backup target.
