Axing Question

I would like to know how yous guys felt (compare/contrast)
Executioner's Strike - does 10-34 dam. but takes 8 adrn
Penetrating Blow - 5-17 dam. how ever it only takes 5 adrn and has an armor penetration of 20%.

Right now i use Ex Strike but i think that Pen Blow would be wiser as it would charge faster and the armor pen. is a plus...lemme kno what you think would be better to use.