Cgiles,
I am not going to question your evaluation, because -as you say- it's all subjective and what's good for one can be just wrong for another. One thing, however, stands out as just plain wrong to me and makes me think that you need to reconsider your opinion, maybe after a night of sleep. When you say that you hear distortion with the volume knob above 2 o'clock, there is definitely something wrong.
I own a Tyros 2 since the end of October and I have never had this kind of problem, so I strongly suggest that you check your setup.