I have done both.
Most of my snakes are fed in their enclosures. They all know when feeding day is, and they all know the routine for feeding. There is a definite level of excitement on feeding day, but I can reach in any other day with no issues from all but one of my snakes. That girl is blind, and it takes a little finesse on my part to remind her that open tub does not always mean food.
I have used a separate feeding tub to kick start a few reluctant feeders. This was done by placing the snake into a small empty tub, covering 95% of the tub with a heavy, dark towel, then using tongs to hold a live mouse in one spot until the non-threatening movement of said mouse proved too much for a hungry snake to resist. Usually one feeding this way was all I needed, after that they ate in their own tubs.
The debate over this is endless, and each must do what is best for themselves and their snakes. If your main concern is cage aggression, that is about 90% myth. However it is worthwhile to note, if you ONLY open/reach into the enclosure to feed, {And I wanna know how you clean} and/or you make it a habit to handle your snakes food just before reaching into the tub you stand a very good chance of getting bitten. However, I don't call that cage aggression. I call that stupid owner syndrome.
The good news is SOS can be cured, mine only took a few weeks of daily visits to this site, the symptoms improved right away, and I rarely have a relapse!
Gale