2x6 ... It is ok for you to like the tube sound. Your amplifier generates about a 6% THD at its rated power, which translates into a distortion floor of about -24 dB, which is quite audible in the all important midrange portion of the musical spectrum (200-2000 Hz).
As an example, in this range, at 90 dB at a listening position, a pair of M80's will have a distortion floor of about -48 dB, compared to your amp's floor of -24 dB.
A good solid state amp will have a distortion floor of about -60 to -80 dB, depending on the amp - well below that of the speaker, and inaudible.
At this -24 dB level, your tube amp will be adding typically 2nd harmonic distortion, which will be quite audible. It's also, for many listeners, quite pleasant - it is that "warmth" people will tube amps discuss.
Alan's description of the amp being a "distortion generator" may be abrupt in its delivery, but it is quite accurate.
