I think pretty much everyone will say the same thing. Feather is complete nonsense, while cardboard is possible but not that good. I already called both of them stupid.
Oh yeah, fists are really on topic, in IcyGriffin's case.
This is a discussion on whether a cardboard or feather sword is better, not about whether to use a sword at all. I've already said cardboard for reasons given in this thread.
Feather sword because you can tickle your opponent until he drops the cardboard sword, then jam the cardboard sword in his eye while he's rolling on the floor laughing.