Those PC's look like great value and availability and are clearly very popular - have squeezed out other options like Intel NUC. Very tempting.
But I've heard that you pretty much never get a BIOS update and the quality of any such update is going to be dubious. Nothing sinister about this - it is simply a bargain basement option.
So, you are really throwing security out the window.
Security shouldn't be much of an issue with most modern CPUs. The microcode can be updated at boot time by the kernel, even if the one loaded by the BIOS is out of date. So microcode level patches are taken care of.
That leaves attacks on secure boot, which could be feasible with a bad implementation, but I doubt most home users would have to worry about an evil maid attack.
But I've heard that you pretty much never get a BIOS update and the quality of any such update is going to be dubious. Nothing sinister about this - it is simply a bargain basement option.
So, you are really throwing security out the window.