For that type of appliance, I'd rather have OpenWRT than Ubuntu. Comes pre-fit to the job at hand. And with a reasonable secure configuration by default, as opposed to whatever the thing you've hacked together yourself accidentally leaves open.
That said: Having medium-powered, cheap, compact and appliance-like general purpose computing available is certainly a nice change.
Big computers with lots of cores and gigahertz gets boring pretty quickly. These kinds of things sort of takes computing a bit more back to its roots.