Although this book held my interest (fun concept; characters that you cared about; well thought-out and detailed descriptions of the potential problems that we take for granted), I can't really recommend it because there was a lot that I found objectionable, offensive, and even disturbing.
Sometimes, there are sex scenes in sci-fi novels - what you do not expect are scenes of the following: rape, lesbianism, S&M, bestiality/rape. These scenes could easily have been removed or at least re-written for broader audience appeal. As such, they are not just (at a minimum) offensive but, in some cases, disturbing.
Additionally, there is a great deal of latitude given to the Bronze Age paganism, casting some as very evil, but others as "nature-based", and therefore admirable or "good". This "some are good, some are bad" is extended to the Christian churches sent back in time. In that sense, there is some fairness/equality, but there is definitely the feeling that the goodness of the pagans and the madness of the evangelical Christians are given more pages/words than their opposites. While a couple of Catholic priests and some other "mainline" Christians are depicted as "good people", Christian morality is viewed as passe while the evangelical Christians end up inciting a riot and commiting arson "in the name of God's judgment".
The problem-solving of trying to remain somewhat modern with bronze age means was very intriguing. Also, the descriptions of battles (both tactics and strategies) were very well done. Overall, this would have been rated 3 or even 4 stars, but the scenes of sexual depravity and depiction of Christians as homicidal fanatics means that I honestly cannot recommend this book to anyone I know.