I am a HUGE Tull fan. My dad was a biker and listened to all the great 60's heavier stuff. I remember the Aqualung album from when I was knee high. I got into a lot of their other stuff when I was growing up. My favorite songs are One White Duck / 0" = Nothing at All and Jack Frost and the Hooded Crow.
I got to see them in '92 or so. They were super good. Still really tight as musicians.
My uncle saw them in the early 70's. Said it was one of his favorite concerts. People were being loud, and Ian stopped the song in mid verse. Yelled at people to STFU. Then went one, two, three, and picked up from the exact note they had stopped on.
I think that make him less an ass and more of a perfectionist.
I also heard him on a radio show in Seattle where he said his daughter pointed out his technique was wrong and he 'relearned' the flute the 'right way'. Interesting guy.