the book is boring. Lots of exploration, little characterization or action. I don't see a very good movie coming out of it.
Sounds like a description of Clarke's 2001. Sure worked fine there, even though the novel and film are very much separate entities.
I think 2001 is probably the most overrated sci-fi movie of all time. I like quiet, intelligent sci-fi as much as the next person(bladerunner, contact, gattaca, etc.) but 2001 is self-indulgent and tedious, and I think "rendezvous" is tedious as well. I got through it but thought it was a slog.