Guild Wars 2

Do they stack additively or multiplicatively?

~12% Berserkers power, adrenaline
10% Slasing power, with greatsword
10% Attack of opportunity, on bleeding target

What would you get if say you had slashing power and attack of opportunity?

Dual wielding two handers is just straight up goofy. Polearms or landbased spears would be pretty sweet though. A halberd is kiiind of like a 2h axe, 2 birds one stone!

Is it really slower though? It feels really slow but the cast time on the icon says 1/2 for each of the 1 ability attacks. Did you mean the 2, 4 and 5 abilities? They are pretty slow. I try to chain them off earthshaker (doesnt seem to be as obvious/have as much warning) Then 5, 2, 4, 3 then switch to rifle if you wish or go all hulk smash with a fair speed autoattack with high multiplier damage.

If im misinterpreting the meaning of the time shown on the upper right hand of the icon?