Well tbh I can't see Boult playing in the first test, but if he does I think it's more likely that it'll be at the expense of Bracewell rather than Martin.
If we lose the first test, then I think it's likely that Boult will come in for the pace bowler who performs the worst in the first test.
Obviously there's pros and cons both ways in the Martin debate, but I think you've got to have a pace bowler who's been there and done that. Remember that Southee averages 43 in tests, so it has the potential to get ugly for New Zealand if you chuck him in with two pretty much debutant's and nothing's happening for Vettori.