Our ranger used this skill in pvE today and he was knocking back EPIC mobs (tough a few levels below , like 3 levels)1 out of 2 shots.
Tough it was very funny to see Ymirs flying around all da time we has like a mezz that did damage. He would take care of the add and by the time we killedthe first this one wud be half damage.
The % Chance in PVE is still quite high imo and should be nerfed cuz it kinda takes the challenge away for our playgroup

Altough it has given us funny situations ( Shooting a Ymir from point A to B on the other side of the camp to see him fall off the hill and die mid air due to lightning strike)
Greetz