Well, as I'm not a doctor, I can't judge the auscultation qualities of any stethoscopes. Of course, I can hear differences in acoustical quality, but the fine very differences in heart auscultation, I can't judge.
I'm just a simple "Stethoscope Lover", because it's so sexy and erotic for me :-)
It's just as like you love a sport's car, for example: It's nice and sexy, but you don't know any small details of its mechanical content.
Thus, for me, other aspects of quality count: look, feeling, smell.... I prefer rubber tubings, red; heavy and cold brass chest piece, shiny chrome ear pieces...
What means, that for me personally, the "best Stethoscope" is the Haselmeier Supraphon !!!
RedStethGuy