My feelings here are a little complicated, so I'm going to split this into two parts. The first: my thoughts on this book specifically. The second: my thoughts on the trilogy as a whole. 
 First Reaction: 
 ...I'm disappointed, but mostly by the height of my own hopes. The book itself was... fine. Even good in some places. But it wasn't great, and frankly I thought that it tried too hard. 
 I made a quip before I started this about it being a nice bookend, since I started the year with Neal Stephenson's Seveneves. At the time it was a throwaway comment, mostly just poking fun at myself. Now, though, I find it's almost too accurate. Both books start strong, and devolve into wishful fantasy land as they go on. 
 It's clear that Cheng Xin is supposed to represent some fundamental aspect of humanity. Unfortunately, that [feminine] aspect sees her manipulated and sometimes demeaned by various men in her sphere. Although we are told she is an excellent scientist in her own right, outside of the initial setup in the crisis-Era portion of the book, she really doesn't act in that capacity. Instead she is symbolic; a figurehead or archetype for both the reader and her species. In this way, I am rudely reminded of all the time I was forced to spend in Luo Ji's head back in The Dark Forest. Xin is not a person, she is an ideal. 
 The first part of the book was fine, once we switched to Xin's perspective. But as the main driving plot point for the series is resolved, the book becomes less and less interesting. Space Magic abounds, and--due to the wonders of hibernation--rapidly reaches a point where my suspension of disbelief failed. The last Era of the book had me eye-rolling, as there was little to hold it together. (Much like the last 3rd of Seveneves). 
 I'm not sure that the first half of the book redeems the rest of it, but I'm choosing to give it 3*, much like I gave the last volume 4*. 
 Final note: I am thrilled beyond words to have Ken Liu back as translator. 
 On "Rememberance of Earth's Past:" 
 I did enjoy this trilogy. The first book will probably always be my favorite, and--stylisticly--I do prefer Death's End overy The Dark Forest. However, The Dark Forest connected to Three Body in a way that this final volume did not. 
 Plot points introduced in the first book find their final resolution fairly early in the third, with the remainder of the book dealing with implications from the second. 
 This trilogy was an extremely ambitious project, and I respect that. But only the first book really blew me away.