The 30W per channel (pretty low power) tube amp has its distortion rated at only 1W. Its distortion at full output is probably horrible.
Its damping factor is not mentioned probably because it is very low and it allows speakers to resonate.
There is no guarantee on how long the tubes will last or how soon the distortion will be much worse.
Funny how the people who come from the valve era wouldn't consider going back to valve amps
Perhaps we know something?.