I recently read Rendezvous with Rama and loved it. The prose read as any paperback, but I just loved the fantastic imagination.
A beautiful idea - and then it created a world around it. I have not read many literary science fiction, but the reason you don't miss the literariness is that the richness and the beauty of Clarke's ideas is amazing. Introduced for the first time, the concept of the alien spacecraft with its own ecology leaves you enthralled. Set in it is the wondrous cylindrical world described in detail. Through the book, it leaves your mind beautifully applied traversing concept such as, shifting gravity levels at different points in the craft (and how it would feel) or, wondering what would you see on the horizon if you were in a world which closed in on itself (inside a huge cylinder with scores of kilometres circumference rather than being on a sphere where the horizons tapers off and declines).
Your imagination works in tandem with the author's and you come out enriched from the read. One realises in such books that narrative or characters are relevant only for the book to move forward. What you are truly after is the fabulous imagination. It was a short read with lot to think about. And had a positive feel good atmosphere around it.
And it really made me look forward to Rama II. I realised once I bought book two that Arthur Clarke had just provided the outline, the writing was not his. I still tried to stay optimistic remembering the science delights offered by the first book. But book 2 was a big let down. Earlier, I was keen to finish the series (there are two more books) but now, I give up. I cannot endure more of this. I need to recreate my AC image by reading some of his short stories or other writings.
What put me off Rama II? For one, Rama II had some really poor characters in the book. And also, it reads like some kind of Hollywood movie script rather than science fiction. There is very little science, and very little newness to the wonderful concept of book 1. All it does is some incremental build up. And worse, it becomes a paperback with series of poor characters. One is forced to wonder that what has the world come to, if within the sample of people selected to go to meet an alien spacecraft, only 20% are good souls or what you call excellent people or heroes. All other are self serving individuals, or more easily defined as villains in Hollywood terms. Their thought process defies logic. Situations are built up the way it happens in cheap thrillers. May be, it was written as drama, but that is not what you wanted to read after the huge excitement of book 1. It does not make you feel very good, and is something that you can easily do without. It doesn't intrigue. It irritates. And I am glad it is over.
In summary, Rendezvous with Rama (the first of the series) is worth a read. It had good characters, and anyway, the people are secondary in that book. It is the massive idea and mystery of Rama that dominates the book. From Rama I, I also had a list of things to further look up and understand including the double sunsets of Mercury (!?), Coriolis effect, further daydreaming about a cylindrical world, and a keener desire to read up all the sci and cosmos books sitting next to me.
But Book II can be easily missed. All the pleasures are well contained in book 1.
Another thought that I take away from all this is that when people write about ideas, and try to create stories around them, they are better dealt in short stories, or novellas (And AC's short stories are some of the best sci fi ideas). If you try to spin too much around one single idea (without any characters with depth), be it a book series or a television series, it is bound to disappoint.