well first of all: pilots FLY the aircrafts. they don't choose which type to buy. second: if you are new to both (737/320) how the heck should you know the pros/cons of the ops?
whatever.
legend has it airbus couldn't promise the 320 would make it to the canaries on a windy day, so hlf and the unspeakables took the NGs. the 320 are fine for the shorter city shuttle routes. and of course, the more you order, the cheaper it gets.
good luck for your interview (bring some spine for those who are in already).