During the production of 2001: A Space Odyssey, Kubrick and Clarke could not agree on how to depict their aliens. To break the impasse, they sought the help of Carl Sagan who wisely suggested they not depict them at all. Reading Rendezvous with Rama, I feel that Clarke rather liked this idea and made this a whole book exploring it. It's a dripping faucet of first contact stories.
And that is exactly what I loved most about it. The characters are paper dolls and there is very little drama or plot. There were only a couple instances where I felt that a person might be in danger. Late into the book, the only good exception to this arises. It was the only disaster faced by the crew exploring the ship where I felt things might go south. The rest of the dangers or setbacks didn't feel like they had tension. Rather, they exist with the purpose of giving opportunity to drop more of the mystery to you.
This may sound like I'm trying to drag Sir Clarke and, well, only a little. At about 4/5ths into the book I was starting to get a little impatient with the lack of tension. What tension there is, it is supplied by the reader. Your impatience to know more and questions you can't answer are the drama. And I haven't read another book yet that comes anywhere close to the peaks of that drama this book has.
A couple ideas here I think will really stick with me. Like the biots(neologism, biotic robot) that exist as the caretakers of the ship. When the ship begins to warm with its approach of the sun, a large cylindrical sea thaws that contains quasi-organic molecules that, through unknown processes, begin to be shaped into creatures with specialized roles. There is a janitorial crab being that I am convinced S.A. Corey were inspired by for their proto-molecule creatures. My favorite were the tripods. They whirl about like dervishes, using their three radial eyes--Ramans do things in threes--to observe the interior of the ship. Reporting back to something...or nothing.
If you read this book, it will be one of those books that make the ideas in other books seem less original. I frequently found myself thinking "Oh, I wonder if [x] was inspired by it."
Clarke's writing is not my favorite and it can be a little boring but Rendezvous with Rama is absolutely world-class and I believe it deserves recognition in the Sci-fi canon.
Overall, I give it 7/9 Biots.
(oh and, there are creatures called Super Chimps on the human ship and they shorten it to 'simp.' I found myself laughing every time they were mentioned)