Dual Blade Guide (Chaos, Big Bang, and Pre-Big Bang)

Both Final Cut and Blade Fury (in relation to Upper Stab) offer about a 23% increase in damage, except Final Cut affects all of your other skills as well. Actually doesn't max FC give a 35.71% boost in damage (disregarding the time and damage of the actual FC attack)? (And Blade Fury 23.75%) (And Sharpness 11.55%) (And Thorns 12% if you have 250 total w.atk)

I already posted in the other Chaos build thread about the strength of Slash Storm, and I think a post by JoeTang a long time ago "confirmed" it.

Edit: http://www.southperry.net/showthread.php?t=34932