Ah, I forgot the most important part:
R. Ilson was a talmid of R. Soleveitchik at YU for 10+ years. He received smicha from the Rav before marrying the daughter of one of the Ponevitch Mashgichim (the shidduch was made by R. Shneur Kotler,with whom R. Ilson was very close, if I remember correctly) and moving to Israel. He was originally Rosh kollel at Torah Moshe (R. Meiselman’s yeshiva), but left to open his own Yeshiva due to hashkafic differences.
As a Brisker, R. Ilson tries to give over a particular derech to his students that teaches them to learn simple p’shat in the gemarah and rishonim by “reading the words.” He is not fond of pilpul and “reid.”
He is a truly brilliant mind (working on sefarim on Ohalos, Chullin, and Sefer Hamitzvos), and has a very likable style of saying a shiur. Very warm and personable with his talmidim one you get to know him (you need to make the effort) – in learning, but also in personal matters (e.g., he will occasionally IM me if we both happen to be online at the same time to see how my life is going, ect.).