Chaikin's book is excellent. Two books on Apollo that I'd recommend:
1. How Apollo Flew to the Moon, by W David Woods. Don't be put off by the cheesy cover, this book goes into a lot of technical detail and does a pretty good job of explaining things.
2. Digital Apollo by David A. Mindell. A detailed look at the use of digital technology in Apollo, particularly for guidance. Lots of chewy technical detail.
These books would definitely appeal to many HN readers with an interest in spaceflight.
I haven't read either of the books you mentioned, but "Apollo" by Charles Murray and Catherine Bly Cox is also excellent. From the looks of it, the paperback is hard to find ($125 on Amazon!), but the Kindle edition is only $8.
The HBO mini-series, From the Earth to the Moon, largely based on that book is also quite excellent. Go find it and watch it. -- http://en.wikipedia.org/wiki/From_the_Earth_to_the_Moon_(TV_...
If you're still looking for more material after that, I'd go read "Failure is Not an Option" by Gene Kranz.