Maybe I should join in. I haven't played ANY of my 5.1 Tull. I think I have them all except Aqualung (being reissued!!!) and Too Old, which I'm not particularly interested in. Do you recommend one to start?
Recommend starting with a 5.1 classic in the form of "BENEFIT" (for your benefit of course).
Those 2 Aqualung discs showing each contain a quad and 5.1 disc from the box set, btw. One a dvd the other blu-ray.