Rogues with Katana only have one -Aggro Rune. Other classes with one weapon either have ISS, regular Skill or Elite Skill to reduce aggro.
Classes like Rogue/Mage, Rogue/Priest, Rogue/Warden, Rogue/Druid and Rogue/Warlock have massive aggroproblems if played with Katana.
I think there are three options:
1) Adjust those five classes to have an Elite Skill for -aggro
2) Generally add -aggro if mainweapon is Katana for Rogues
3) Adjust 80 ISS to also reduce aggro
I prefer 2) because the aggroissue is only prevalent for Rogues with Katana. Rogues with multiple weapons have no problems and imo should not benefit from this.