I found the book a VERY mixed bag.
I just didn't get into the first third of it. Way too many scenes of people talking as a way to recap what has happened in the other books, recapping what has happened in Borg TV episodes, recapping romances from the show, etc. Then after all that there's a conversation that seemed to me a recap of the prologue. I started a list at one point because I couldn't believe the number of references there were as opposed to anything new. We all like references to things in the show but this was way over the top I thought. I was pretty surprised considering the what I thought was a pretty good track record for Christopher.
After struggling with GttS for days I read the last third in one sitting. I think the last third is probably my favorite part of TNG-R, which admittedly isn't saying tons but there you have it. Once we're done with the all the set up and get into some story it really picks up. A lot of good action scenes and talks about Picard and a family kind of thing.
And Leybenzon's final screw up was just amazing. What an awesome ending.
I skimmed through this thread and went and read the Amazon review Christopher mentioned and I found it to a rather fair review. Yeah, not the most flattering but it wasn't a hit piece. I can't disagree with much of what the review says.