Those of us who are learn daf yomi (Chulin)now know what Rav Moshe zt’l meant when he stated in his t’shuva that Chalov Stam in the United States is like Chalov Yisroel and those who are a Baal Nefesh should drink the Chalov Yisroel.
So what is a Baal Nefesh? A Baal Nefesh is someone who goes beyond the Ikor Hadin which is determined by the reasoning of “Rove”, and follows that which is determined by “Mee’ute” which is lifnei m’shuras hadin.