“2001” looses a lot when not seen in its original cinarama format.
I saw 2001 alone as a first release in an almost empty *huge* Cinerama theater as a boy. It was a weekday matinee, and I think my mother and grandmother were shopping next door. That theater was later divvied up into 2 or 3 theaters.
Needless to say, it made quite an impression.
And I should know, because I saw both kinds of films, as well as 20001, when it first came out.