I think the Ice Breaker nerf was unnecessary, never heard anyone complain about it ever. But in all honesty Black Hammer was overpowered against bosses, no game developer would ever intend a weapon to be that effective. It hurts me as much as it does you (I have three, all levelled up and ascended to 365!) but its a bitter pill that needs swallowing. Would have rather seen a more creative adjustment than that, or at least a much bigger reserve ammo capacity buff.