I hate saying unpleasant things about other people's work because I'd hate it if they did it to me, but on this occasion I have to make an exception. Cradle has to be the worst book I've read in ages.
The problem lies not in description or character interest but in plot and setting. The whole alien business which is supposedly the subject of the book gets pushed to one side by long soap-opera stories about the pasts of the characters, some of whom actually do virtually nothing to affect the main story (e.g. the naval commander, who turns up at the end after taking little or no active role up till then and suddenly gets made to feel good about himself again).Between them, the human characters must have just about every emotional problem known to man! Also, nearly everything to do with the alien ship is obvious to the reader but not to the characters by about halfway throughthanks to the chapters about the aliens, and the one major thing not revealed gets sorted out no problem by the characters after a quick bit of soul-searching. Actually, I have just realised that the whole story resembles nothing more than one of the duller episodes of Star Trek: The Next Generation. Finally, an interesting plotline - the message to the aliens from "Power #2" - is not developed at all.
The setting of the novel in the very near future also denies Clarke the chance to use one of his greatest skills - the projection of humankind's future development. This is usually the best aspect of his books and is totally lacking here.
Clarke and Lee can do considerably better than this. I have read another of their collaborations, Rama II, which also puts a strong emphasis on character description, but not nearly so much at the expense of plot.
If you want to read some good revelatory Clarke material, I would recommend Childhood's End, which is a really ingenious work. Cradle, I am afraid, falls well below his usual standards.