From these:
we can see that the level 122 Turtle Assassins has a 2889 minimum atk, compared to the level 122 Skeleton Swords which has a 4104 minimum atk.
Also the Turtle Assassins gives 1.830.125 experience against 1.412.850 for the Skeleton Sword.
From there I calculated that new mobs hit 33.77% less and give 25% more xp.
Tell me if i'm wrong but i seems correct