*Spoilers Full Speed Ahead*
Although the plot couldn't be any more different from The Remains of the Day (what an awkward title!), from the minute you start Never Let Me Go there is no doubt that it was written by the same author. The restraint and reserve in Kathy's voice match's Stevens and of course there is the unrequited love that both miss just by the tips of their fingers due to their reserved character (although Kathy gets at least a little bit of it at the end). Both novels also discuss man's humanity in ways that make you feel that although as a whole our society can be monstrous, that amongst this horror there are shining stars of humanity, especially if you look for it exactly where you don't expect it.
Never Let Me Go takes you on some twists and turns at a sometimes exhaustingly slow pace, but if you stick through it, by the end your more invested in the characters and their fate then you realize. And although perhaps it couldn't end any other way, the ending leaves you feeling slightly depressed and unsatisfied. Why hadn't Kathy and Tommy run away to spend whatever time they could together? Perhaps it wasn't in their nature, but you wish that they had and that even if there were to be a bloody ending to that path, they would have at least gotten to spend whatever time they had left on their terms and with each other. I think they would have been happy with that.
I won't give the big spoiler away, but I will say that I was unaware of it for most of the first part of the novel, which obviously was Ishiguro's intent, and that it made the novel's message more powerful for me, so I'll leave that for you to discover on your own. If you have the time and patience for this novel, it is well worth the read. It gets in deep with you and forces you to view humanity with a much more cautious eye.