Its an illusion sort of...imagine dice rolls...you have a weapon that deals 1d10(normal), and another that deals 1d6(normal) and 1d6(magic)... The 2d6 is clearly an upgrade because you have a chance for 2 more damage over the 1d10..but for the most part it will seem about the same until you deal with resistences...in a fight where a creature takes 50% more from the magic element you have a chance to upto 15 damage. But its a double edge sword, no pun intended, cause if they have resistance to your damge you lose some.
