olympos could never be the same as ilium - as the idea/themes of the story had been partly revealed - so olympos had to be different and dan simmons has done that.
the plot breaks up into many different story lines - you will or may have guessed some of the answers but other plot lines may come as a bit of a surprise.
as you get closer to the end of the book you wonder if there is a 3rd book you did not know about - how are the stories going to end in such a short space of time. the only disappointment is that it seems to fall into the space opera trap of just a couple to many coincidences saving some of the story heroes and the day. with the odysseus story perhaps the most puzzling quick ending.
some may not like this book after the pure new joy and excitement of the 1st book but if you have read ilium then you have to read this.
and at the end of the book dan simmons gives a right old bitch slap to those who complained about the detail of the extra background characters in the battles and stories.