i prefer f/t . for a few reasons. the safety of the animal, if you have a larger collection its aloy easier to have a few hundered frozen rodents around than live. we freeze alot of human food to keep it fresh etc. does it mean that your frozen peas or steak are less nutritious ? im not sure, but ive raised hundreds of snakes over the years and they have always done fine. but ive always said if it aint broke dont fix it, do what ever works for you because if you ask 10 different people you will get 10 opinions