I started The Last Days of Krypton a couple days ago, but yesterday I decided I was in the mood for more Trek instead, and switched over to Paths of Disharmony. I'm a big fan of the TNG Relaunch and the Andorians are one of my favorite Trek races, so I've been looking forward to this one.
I heartily recommend THE LAST DAYS OF KRYPTON. It's been at least three years since I read it, so the details are sort of fuzzy, but the book itself stands out in my memory as a very enjoyable read.
I also recommend, if you haven't checked it out yet, ENEMIES AND ALLIES, by the same author. It follows Superman and Batman's first meeting the the 1950's. It's not a sequel to KRYPTON, but an enjoyable book on it's own.