I feed my corn snake in a separate container, cause that's how I was taught it was done via the corn snake forums. I think it's because corns tend to be kept on aspen, which is easier for them to accidentally swallow. At any rate, I have zero issues with it. She's associated "critter carrier = food", and she knows what to expect. The routine goes that I put the critter carrier on the scale, zero it, and put the snake in for pre-feed weigh-in. After that, I open the little hatch, put the mouse in via tongs, then she strikes and eats. I close the hatch while she eats so she can't escape, and just let her take her time. Once she's all done, I open the carrier over her tank, she slithers back in, and all is well. I know people say you can't train snakes, but she definitely knows the routine by this point (had her for two years now).

Now, I just got my BP, and I think I'll try and do that same routine with her. If she ends up being too shy for it though, I'll just switch over to feeding in tank. I'll just put a paper towel down for her or something.

I think the biggest plus to out-of-tank feeding for me (besides the not having to worry about eating substrate) has been that it doubles as a weigh-in day, since I keep records of weight to make sure they're eating properly. I need them in a container on the scale for that for that anyways, may as well feed them while I'm at it. It's not a big deal for me though, since I'm just now getting two snakes. Could see that not being an option for someone with a bigger collection though, and I don't blame people for feeding in-tank. As long as the snakes are okay, I suppose it really just comes down to personal preference.