Dear Matteo:
Welcome to the thread!…
As I was the one who started this particular thread, I did so because I TOO am debating whether or not I can justify spending over $400.00 U.S. on a resin instrument, (though I am very much convinced that it IS a good choice…)…therefor, I have not yet had the opportunity to play the Bernolin Alto…
That said, I own and play, both in the soprano and alto ranges, the 700 series Aulos instruments as well as the Yamaha 400 series/Ecodear instruments, (as well as the 300 series Yamaha resin instruments).
In my humble opinion, for what it is worth, I would rate both the Aulos AND the Yamaha ABS/resin instruments relatively highly for what they are…(roto-molded instruments)…I have purchased these instruments, (along with even more, (fine wooden instruments)), from the “Antique Sound Workshop”, (A.S.W.), where A.S.W. indicates that it corrects for intonation issues. With these resin instruments that I have purchased and played, I find that they all possess good intonation and response, and with a little care and fineness all are capable of playing very well. Perhaps I would rate them an overall rating of 7(?)…
THAT said, they ALL possess some different characteristics…From MY experience, the Aulos 700 Series are fairly free blowing, with a relatively complex, “buzzy” timbre when played with higher breath pressure. The Yahama 300 Series is also fairly free blowing, with a somewhat blander, perhaps slightly warmer timbre…and the Yamaha 400 Series/Ecodear instruments seem to exhibit somewhat more air resistance, are quieter, and produce an audibly “rounder”, more “mellow” if not blander timbre, the alto in particular!…). I HAVE also found that they DO tend to clog a bit more quickly than their other resin “cousins”.
As a “solo” instrument, or playing in a mixed consort, I would be more inclined to select the Aulos 700 Series instruments…as they are a touch more “distinctive” and/or brighter in timbre, with the Yamaha 300 Series coming in a close second for that application. In more general use application, I might select the Yamaha 300 Series, as it blends slightly(?) better in ensemble, but still yields good dynamic range. For purely recorder ensemble application, (where blending is principle prioritization, I would select the Yamaha 400 Series/Ecodear instruments, which appear to blend well together due to their inherent mellow timbre as well as their somewhat more limited dynamic range capabilities. In addition, for inexperienced players/children in mass(?) learning to play sopranos, for a relatively inexpensive, VERY durable plastic instrument, the Ecodear’s are so very welcome!… 🙂 …
I realize that I did not address your PRIMARY question/comparison with regard to the Bernolin instrument(s), however, I hope that my experience/comparison with the Yamaha and Aulos instruments might provide a modicum of value to you?
Peace/Namaste,
Tim K.