SB or Mistress support/shred who done it better?

Which class ends up being better solo and group wise?

I know Mistress shreds Elemental or Magic def(excluding gear). If you want to have the extra damage you sacrifice the shred.

Soul Bender Shreds Shadow and both defenses. Doesn't seem to suffer from the same downfall as Mistress.

Mistress has more holds? Also he seems to have better weapon choices as well. while Mistress loses out if not using a scythe.