(I believe the chosson in the picture is ylct"a Rabbi Boruch Lederman shlita, who was with me in Rabbi Niman's shiur. While other pictures in the accompanying links show Rabbi Niman older, this is the way I remember him.)
I was in Rabbi Niman zt"l's shiur for a little over two months in 1980. It was a unique and wonderful experience. His Ahavas Torah, his Simchah in Torah, his Sever Panim Yafos and his affection for his talmidim were outstanding and inspirational.
The time spent in his shiur was an intense experience of the "Chofetz Chaim Derech." The sugya I remember most vividly is the sugya of bsar mei'ikara/bsar sof at the beginning of Eizehu Neshech. It was an exhilarating experience that has stayed alive in my mind all these years.
Years later, when I occasioned to meet Rabbi Niman, he was as warm and welcoming as if I had spent much more time in his shiur.
He was a role model of a quintessential Maggid Shiur.