I have been powerfeeding my fish for 20 years.
only problem I have is that my fish live for years and years until I get bored with them

(provided you do the required water changes to go along with powerfeeding)
powerfeeding to me, is just feeding until the belly of the fish is visibly full.
each day.
now, sometimes if I am feeding a high protein food, I will only feed 5 or 6 days per week to give the digestive system a break.
fish growth is still very rapid.
right now, for example, I am powerfeeding 5 small tinfoils in my 150 (see my sig) along with 5 filament barbs.
a powerfed fish living in clean water is a healthy fish in my experience.
and will grow and live for years and years.
I know there is another thread about 'fat fish' and how it is unhealthy, but at least in my experience,
a fat fish = well fed fish = healthy and long lived fish.
I disagree that powerfeeding is bad. as long as you do the required wc's to compensate for the extra waste.