I have Debian running on my TS-451A for quite a while now. Except the front LEDs, everything is working completely fine. It is pretty much just a plain x86_64 PC with an UEFI firmware. The TS-251A is exactly the same but with 2 instead of 4 drive bays, as far as I know.
It's very neat for its low power usage and small form factor.
It's very neat for its low power usage and small form factor.