I wouldn't use systematic AA, most of the times, it's a waste of time (unless you are rendering with DOF or Motion blur, and in some indoors renders with GR lighting).

It doesn't make much sense to set Min and Max AA to the same level, because you are telling Vue to compute 9 levels of subrays all the time, even if they are not needed. Put a smaller value for minimum. The threshold should be raised also if you switch to "optimized" instead of "systematic". I go for 60% myslef.