Crossroad Killer Or Bobs Mythic Daggers?

I have been toying with a build for a level 75 assassin this is what I have so far.

Executioner Helm (for life steal and mana steal)
Millenium(for spell dmg and health regen buff)
Electrocharged grieves with +2 attack speed
Sodeta Boots (again for life steal and some mana regen)

On the attack dummies in Troms my spin attack with bobs daggers is actually better than with Crossroad killers. I am sure that this is due to the -spell on CK but I thought CK was the best weapon for a glass cannon build. Am I wrong?

 

By the looks of it, Crossroad Killer is a melee weapon; it's better at just plain attacking than it is at performing spells. Use it if you want to melee.