Hi Guidocorona,
It was one of the earlier Class D amps, though I don't recall the model number. I bet it was still low on the learning curve and subsequent models have been improved.
I am hesitant to talk about "tube magic," because it means different things to different people, and because MOST tube gear I hear completely lack what I look for in tube gear (particularly, high-powered pentode amps driven by KT-88/6550s disappoint). In my setup, I did not fully get what I was looking for until I found a suitable tube linestage and a tube phonostage to match with my parallel single ended triode amp. The Levinson No. 32, which I still keep as a backup, did not quite deliver what my Emotive Audio Epifania delivers.
I am not saying that tubes are superior. In systems where more power is needed, I think that solid state is often much more desirable than high-powered tubes -- different horses for different course. I bet Class D would be the appropriate choice in some applications. The point is, one cannot make a generic choice, trial is the only reliable method. Also, I think one will usually not find success trying to compensate for strengths and weaknesses based on perceived individual qualities of particular components; the results are too haphazard for that.
There is a lot of practical sense in sticking with one brand for amplification or to go with an integrated -- usually, a good designer has worked out such compatibility issues.