Fair enough, but from the little experience I have in this game, when you know how to cornershoot with a shotgun constantly, big dmg for knockback is even better than high firing speed. If the opponent never reaches you due to knockbacks why should you bother increasing your low firing speed? With the 2 reloader plus shottyman, you don't really need firing time with a shotgun, while it is a plus I don't deny, I think it's superfluous. Piercing armor on the other hand, feels amazing when you can kill barons with 2-3 shots from a range of 2-3tiles, without risking your life at all. Saves ammunition too.