I think the first thing that needs to be addressed in a thread like this is your definition of power feeding. A lot of people have different ideas of what they would consider power feeding.
Personally, I've always had the understanding that power feeding is forcing the animal to eat more than they should by passing multiple prey items to it one after the other in a chain. That I believe is wrong, and the stress you would cause the snake out weighs any benefits you could gain from doing this.
Some people consider feeding more than once a week power feeding. I don't see this as power feeding. If the snake isn't hungry, it's not going to eat. As long as you're keeping an eye on the snake to make sure it's not becoming obese, there's nothing wrong with this. If it IS becoming obese, you're over feeding the snake, not power feeding it. I believe some snakes are genetically predisposed to eating whatever you put in front of them, so you DO have to know your animals.