Horses for courses i'm afraid.
There is no 1 simple answer to that Question.
It depends on the Technique, what the fish want on the day etc etc etc
Pole fishing could benefit from soft expander pellets, where as Feeder fishing or Waggler fishing would probably be better suited to Hard Hair rigged or Banded Pellets.
Try experimenting on your Water / Waters to see what works on the day, as all things one day is not the same as the next.
