you can be as harsh as you want, but I have been keeping fish for quite a while now and hardly ever use feeders. Temensis, however, are very picky eaters and are almost impossible to feed only non-live foods. I have had them eat pellets and blackworms, but they just don't beef up on those types of foods. They will obviously eat some when they are real hungry, but usually they will just ignore a pellet. There is no way anyone can afford a strict diet of blackworms for these monsters, as they could easily go through 3 lbs. in a week. I feed them feeders maybe once a month to give them a really full belly and a little excercise, and I find nothing wrong with that.
The fish in the first picture is a crenicichla lenticulata.