While this book was no where was good as Atonement, I did find it quite interesting and a clever novel. While I found parts of it frustrating while reading it, it was one of those books that grew on more once I finished it. Always one to be adventurous, McEwan doesn't hold back from trying atypical form and unconventional styles. In this book, he jumps time often and never quite gives you enough information to make full meaning about what you are reading. Perhaps this is why the ending was so satisfying, and a bit of a saving grace.
For much of the novel, I found it a bit annoying and frustrating (a McEwan theme for me). Often the plot moved too slow and pages would go by with too much fluff. He's both a great writer and one that is hard to follow. Often not linear and concrete with describing actions, I do find myself having to pay a bit more attention than I do with other books. I wouldn't mind this as much if a break was given from time to time, but I find him often short on dialogue (which usually is much clearer) and heavy on convoluted prose. One other negative - I found most of the characters pretentious and hard to root for.
With that said, it's still a pretty engaging book. It starts off with a great opener and immediately draws you in as he takes his opportunity to jump into the future and share the dystopian landscape (I know, similar to so many other books at present). The novel then moves toward a bit of a Tenacious D focus (yeah, I bet not a lot of people make comparisons between Tenacious D and Ian McEwan). In this case, much of the novel centers around a poem read at a dinner party that is considered by many the greatest poem ever written. Similarly, Tenacious D has a hilarious song called Tribute (lyrics here). The joke of it is that there is a song that is well known of the greatest ever but can't be revealed or sang; I felt like it was the same bit here with this novel.
Overall, I think this book is worth the time. It's not a super long read and the ending is thought provoking. In fact, upon completion, I found much of the book thoughtful. Finishing it, you can't help but think about some important themes - how accurate are memories, how serious are the environmental challenges, what are the many forms of love, etc. If you can get past the time jumps and difficult writing style necessary for following important plot/character developments, the book is probably worth your time. 
