Distortions that the human ear likes. Are there any ?

Well I don't think it could Rilly be better. If it were, then the more tape copies you make from the original tape, then the better the result should sound, yes??

You might, I suppose, indeed come up with a preference for a single-generation copy tape to the original vinyl, but if your system's response were being continually improved by other means, would you come to the point that all you preferred was the vinyl?

But then, I can't rule anything out either...the above is just my 2 cents.

I was playing hooky yesterday, but I still would answer the OP by saying that fundamentally speaking, that I don't think that there are distortions that we might prefer, just those that we might think we prefer until we hear it done better more properly and come to prefer it instead.

When it comes to harmonics (and I realize this thread is about whether or not we might "prefer" any certain kind of distortion), then overall I'd think that the most "realistic" reproduction of harmonics across the board would be the one most immune to criticism. But, then I don't think in terms of arriving at the best "recipe" for harmonics, but in leveling the playing field for for devices that are supposed dish out harmonics somewhere close to their original relationship.

To do that, we need to look at the biggest cause (IMO) of less than ideal harmonic performance and that is the "other" harmonics - line harmonics - or the "bad" harmonics. Cancel out those and the good harmonics come out unscathed, in virtually any system. And that's more of a noise-floor reduction/power-factor correction thing.