JR’s review published on Letterboxd :
A young Steven Spielberg once famously said that this movie was like "going through the Prado without lunch". He wasn't entirely wrong.
This is easily Kubrick's coldest, most pitiless picture. Something like 2001 may have been more interested in humankind than humanity, but it had a wonder and curiosity that's entirely absent here. Barry isn't a subject, he's a specimen, and we don't follow him, we study him. We don't have a stake in what happens - but we do find what happens profoundly illuminating.
Also, I am glad, or maybe relieved, to report that this does in fact get faster on a second viewing. Like 2001, no one will ever describe it as swift, and like 2001 there isn't a wasted moment.