MAB on a weapon sucks period when you have potency staffs.
SE needs to change that, its stuff like that that tells me SE does not do testing.
Alkimi is prob right, I really cannot math it out because of all the new situations and gear though.
I will say this though, at 75 when I did do the math for that, the mab needed to match HQ staffs was 25-33 MAB ( the 33 MAB was more for ice nukes because of INT on the staff)