i usually get the REEF seachem.. i think it's preference, but i think the others are right...
i don't know too many people who put tap water into their tank, hence why the dechlorinator isnt' that big of a deal...
but have you noticed they put a tinee winee bit of copper in their salts?
isn't it an odd thing, considering there's probably plenty of copper going around, anyway? (i.e. LFS treatments residual when you throw out their water and acclimate with your own.. some tiniiii bit of copper probably still gets into your tank...)
MayoK