A lot of people say it will cause the snake to bite you when you open the cage, since they associate the cage opening with feeding time...I've never had this problem with any of my snakes, and I feed them all in their enclousures. But it's a matter of personal preference, really. If you want to feed them in a separate container, and your snakes eat fine that way, then more power to you.
I agree with spix14. I take Furio out and put him in a big plastic tubbed filled half with bedding and the other half empty and put the heated up mouse on the empty side and he doesn't seem to mind
I have a smaller enclosure that I feed in. I have also used a plastic tub with good results. My guys are both good eaters usually. I have had some refusal to eat, but that's usually around shedding times. Guess I'm lucky about it.