I'm jumping on the Bobwagon here! 
 I love the light tone throughout and the geek humor mostly relegated to names one AI clone gives to oneself when faced with a profundity of oneself. Riker? Number 2. Of course. But the rest is just a fantastic ride of popular references and snark, right, Admiral Akbar? 
 Seriously, that was just one of the coolest things in the novel... but the next runner-up has got to be the effortless way we start colonizing the galaxy with each replicant, going back to Earth, exploring the star systems, finding aliens, and of course fighting one little pernicious Brazilian who is racing Bob among the stars and who happens to be a rather dedicated idiot. 
 Oh, humanity is practically wiped out. At least he still has his mission! Sheesh. 
 While this is a light book, it's full of great voice and activity and comradeship between oneself. :) Truly surprising just how much we can argue with ourself when we have a whole universe to grow within. I'm trying to find fault with Arthur, but I just can't. 
 This is delicious SF fun and I have to say it's totally accessible for anyone. It may be appreciated more by geeks, however. :)