In hindsight I wish there had been a lot more science about the nature of Einstein's brain. Just today I've read of a study showing that the two lobes of Einstein's brain had a higher than normal number of connections, so not only did his brain survive the trip, its structural makeup may have more value than portrayed, in approximately one sentence, basically, in the book.
At any rate, the book was a brilliant concept. It also contained enough human interest stories -- none of them at any great depth, mind you -- to deserve the rating.