To a new keeper, live rats can be intimidating - they were to me, when I first made the switch from mice to rats.
In my experience, rats are far more calm than mice, any day of the week, and appropriately sized, are no more dangerous than mice.
I feed live exclusively (except for my albino ball python - but I feed him f/t for aesthetic reasons), and have done so for at least five years, with only a handful of insignificant scratches in all that time.