I appreciated the fact there was no coverage of the destination planet and rather than inventing some extraordinary technology the book made few assumptions and used what is familiar or easily imagined. The characters were mostly well developed, all with their own private demons that influenced their behaviors as the plot moved along.
It was unfortunate that not more was made of the evolutionary oath taken on earth in the interim, little made of what humanity had become.
I found the rather cavalier approach to the time passage of their journey and the distances involved in the withdrawal to the lander. Nitpicking perhaps, but these issues were a distraction for me.