I met him a few years ago - he is very low key.

I also met him sometime back -- early '70's -- and while I found him "low key",
I also found him to be an extreme egotist with social capabities so low I
wondered how he might order a hamburger and fries at McDonald's.

He is also very intense - there is a wild look in his eyes that is
midly disturbing.

yup. more than a tad disturbing.