I think Deborah nailed it. This debate shouldn't be debated. In the wild the snakes eat live, so live is obviously fine. But in the wild, the snake or prey can retreat if necessary and so the issues talked about don't normally come into play. The onus is on the owner to carry out what ever steps are necessary to accomplish the task of feeding live while making the snake's well being the first priority.
The reason so many feed FT is sheer convenience. Most people don't want the extra work, expense, or trouble of raising their own prey. So FT is the "Drive Through Window" of snake feeding. It's widely accepted, convenient but still carries the responsibility of making certain it is carried out correctly with the snake's well being at the forefront.
The other part of this debate is always rat vs mouse vs ASF, etc. The bottom line is that a calorie is a calorie. So if you're providing the same caloric value, it doesn't matter the vehicle of delivery.
I have to feed both. I prefer to do FT but have a few picky animals that won't switch so I have to feed live. The only difference I have noticed and perhaps it is just my experience, is it seem the snakes that are live eaters have a slightly better body tone. Maybe it's like eating cooked vegetables compared to raw vegetables. The raw vegetables are supposed to contain more of the original nutrients.
Just my $0.02