Double Crit Dmg on Silas?

I'm mid game, using Silas mostly in anti-air arena, void rift, GB1-2 and GR3. On void rift I'm mostly depending on his ult to melt down the bosses or big guys, while on GB I run hi with rage regen supports and he has his ult up quite frequently. Since his ult ignores defence, would it make sense to swap current Atk% gear to Crit Dmg gear? He currently has one Atk%, one speed and one Crit Dmg on right side gear.