And 2010, the sequel, is pretty unwatchable. It is a bad movie.

The worst part about the movie is Roy Scheider's fatherly internal monologue narration, which tediously explains-like-i'm-five for half the movie.

So maybe that gives us a hint, about what Clark's narration would have done to 2001.

That little sound bite also chimes in over and over again, sounding forced, poorly performed and with a corny distortion effect layered on top, in some presumptive attempt to resonate an idea with the audience. Maybe to remind you once more that the movie is supposed to be a sequel, despite an almost total discontinuity with 2001.

It draws a lot of parallels with Stephen King and The Shining, which had provoked Stephen King to exert more creative control over movie adaptations, often with laughable (or maybe unintentionally comedic) b-movie results.

For sure its no 2001 but I don't find it bad - it has many quality scifi moments I enjoy e.g. Heywood and Russian comforting each other during aerobraking, the brutally tense traversal between the spacecraft and the interactions between Chandra and Hal are interesting if uncomfortable.

Unwatchable? I liked 2010 very much, treasured it on VHS for a decade

It's cheesy, has more of a B-movie feel to it - but I get the impression that the budget was a fraction of Kubrick's.

I still enjoyed it though, and rewatch it occasionally.